| cloning and nucleotide sequence of the highly thermostable neutral protease gene from bacillus stearothermophilus. | the gene (nprm) for the highly thermostable neutral protease of bacillus stearothermophilus mk232 was cloned in bacillus subtilis using ptb53 as a vector. the nucleotide sequence of nprm and its flanking regions was determined. the dna sequence revealed only one large open reading frame, composed of 1656 base pairs and 552 amino acid residues. a shine-dalgarno (sd) sequence was found 12 bases upstream from the translation start site (atg). a possible promotor sequence (ttttcc for the -35 region ... | 1988 | 3149972 |
| cloning and complete nucleotide sequence of the bacillus stearothermophilus tryptophanyl trna synthetase gene. | the bacillus stearothermophilus nca 1503 tryptophanyl trna synthetase (wts; ec 6.1.1.2) gene has been cloned in escherichia coli and the amino acid (aa) sequence of the enzyme deduced unequivocally from the dna sequence of the cloned gene. the predicted aa sequence of the wts enzyme agrees with the previously determined aa sequence except that the dna sequence indicates a third arg residue at the c terminus of the enzyme over the two arg residues indicated by sequencing the protein itself. the t ... | 1986 | 3026925 |
| natural variation of tyrosyl-trna synthetase and comparison with engineered mutants. | we report the cloning and sequence analysis of the gene for the tyrosyl-trna synthetase from bacillus caldotenax and properties of the gene product. the amino acid sequence of the tyrosyl-trna synthetase was found to be 99% homologous with the corresponding enzyme from b. stearothermophilus, with only four amino acid differences. two of these natural variations were found to involve active site residues of the enzyme and correspond to mutations that have been engineered previously in vitro. one, ... | 1986 | 3011073 |
| thermostable alanine racemase from bacillus stearothermophilus: molecular cloning of the gene, enzyme purification, and characterization. | the alanine racemase (ec 5.1.1.1) gene of a thermophilic bacterium, bacillus stearothermophilus, was cloned and expressed in escherichia coli c600 with vector plasmid picr301, which was constructed from pbr322 and the l-alanine dehydrogenase gene derived from b. stearothermophilus. a coupled assay method with l-alanine dehydrogenase and tetrazolium salts was used to detect visually the alanine racemase activity in the clones. alanine racemase overproduced in a clone carrying the plasmid picr4, 1 ... | 1986 | 3015202 |
| cloning, expression and complete nucleotide sequence of the bacillus stearothermophilus l-lactate dehydrogenase gene. | the structural gene for l-lactate dehydrogenase (ldh; ec 1.1.1.27) from bacillus stearothermophilus nca 1503 has been cloned in escherichia coli and its complete nucleotide sequence determined. the predicted amino acid (aa) sequence of the ldh enzyme agrees with the previously determined aa sequence except to three positions: aa 125 and 126, ser-glu, are inverted whilst his at position 130 has been replaced by ser in our sequence. the lct gene consists of an open reading frame (orf) commencing f ... | 1986 | 3026926 |
| amino acid sequences of ribosomal proteins s11 from bacillus stearothermophilus and s19 from halobacterium marismortui. comparison of the ribosomal protein s11 family. | the complete amino acid sequences of ribosomal proteins s11 from the gram-positive eubacterium bacillus stearothermophilus and of s19 from the archaebacterium halobacterium marismortui have been determined. a search for homologous sequences of these proteins revealed that they belong to the ribosomal protein s11 family. homologous proteins have previously been sequenced from escherichia coli as well as from chloroplast, yeast and mammalian ribosomes. a pairwise comparison of the amino acid seque ... | 1988 | 3191988 |
| a specific, highly active malate dehydrogenase by redesign of a lactate dehydrogenase framework. | three variations to the structure of the nicotinamide adenine dinucleotide (nad)-dependent l-lactate dehydrogenase from bacillus stearothermophilus were made to try to change the substrate specificity from lactate to malate: asp197----asn, thr246----gly, and gln102----arg). each modification shifts the specificity from lactate to malate, although only the last (gln102----arg) provides an effective and highly specific catalyst for the new substrate. this synthetic enzyme has a ratio of catalytic ... | 1988 | 3201242 |
| heat shock affects permeability and resistance of bacillus stearothermophilus spores. | heat shock of dormant spores of bacillus stearothermophilus atcc 7953 at 100 or 80 degrees c for short times, the so-called activation or breaking of dormancy, was investigated by separating the resulting spores by buoyant density centrifugation into a band at 1.240 g/ml that was distinct from another band at 1.340 g/ml, the same density as the original spores. the proportion of spores at 1.240 g/ml became larger when the original dormant spores were heated for a longer period of time, but integ ... | 1988 | 3202631 |
| conservation of short patches of amino acid sequence amongst proteins with a common function but evolutionarily distinct origins: implications for cloning genes and for structure-function analysis. | small patches of identical amino acid sequences commonly occur in proteins that have the same function but are derived from evolutionarily distant organisms. reverse translation of such patches into degenerate pools of oligonucleotides provide useful hybridization probes for cloning the gene for the corresponding protein from other organisms. since the conserved patches of identical amino acid sequence are probably important for the protein's biological function, they are preferred targets for r ... | 1988 | 2845364 |
| coenzyme-induced conformational changes in glyceraldehyde-3-phosphate dehydrogenase from bacillus stearothermophilus. | the structure of apo-glyceraldehyde-3-phosphate dehydrogenase (gapdhase) from bacillus stearothermophilus has been refined using a restrained least-squares method. the final crystallographic r-factor is 0.177 for all 53,315 reflections between 7.0 and 2.5 a. the resulting model has been analysed with respect to lattice interactions, molecular symmetry, temperature factors and solvent structure showing that, apart from local deviations due to intermolecular contact, the molecule exhibits a very h ... | 1988 | 3210237 |
| three-dimensional reconstruction from electron micrographs of disordered specimens. ii. implementation and results. | the computational procedures to implement the method described in the companion paper for three-dimensional reconstruction from projections of a disordered collection of single particles are presented. computer simulations are used to demonstrate the way the method functions, and practical aspects are discussed in detail. examples are given of how different symmetries can be exploited by imposing selection rules on the model equations. applications to negatively stained 50s ribosomes and to cryo ... | 1988 | 3212838 |
| determination of sterilization effectiveness by measuring bacterial growth in a biological indicator through firefly luciferase determination of atp. | a bioluminescence procedure for measurement of microbial atp allows a rapid determination of the effectiveness of autoclave sterilization. this determination is achieved faster than detection of acid production in a biological indicator via a ph indicator. bacterial outgrowth from spores on test strips of the biological indicator was detected by measurement of atp using the firefly luciferase reaction. a measureable increase in atp was found after 5 hours of incubation of a biological indicator ... | 1988 | 3213598 |
| biological indicators. | | 1988 | 3225473 |
| permeability studies on protective gloves used in dental practice. | the recent guidelines issued by the dhss and the bds recommend that to prevent cross-infection gloves should be worn by dentists and their assistants whilst treating all patients. little information is available on the permeability of the various types of glove available; this pilot study was therefore conducted, to test five commonly used brands of gloves for permeability to air, electrolytes, dye and bacteria. tests were carried out before and after using the gloves for varying periods. from t ... | 1989 | 2912478 |
| evidence for movement of the alpha-amylase gene into two phylogenetically distant bacillus stearothermophilus strains. | the gene for an alpha-amylase cloned from strain dy-5 of bacillus stearothermophilus was used to examine to what extent the corresponding genes are structurally similar in other b. stearothermophilus strains. the structure of the gene itself was almost identical in dy-5 and a group of strains represented by strain 799. the gene was not detected at all in strain dsm2334, which was phenotypically amylase deficient. comparison of the structure of 5s rrna and electrophoretic pattern of the ribosomal ... | 1988 | 3257753 |
| mechanisms of irreversible thermal inactivation of bacillus alpha-amylases. | molecular mechanisms of irreversible thermal inactivation of two bacterial alpha-amylases, from the mesophile bacillus amyloliquefaciens and from the thermophile bacillus stearothermophilus, have been elucidated in the ph range of relevance to enzymatic catalysis. at ph 5.0, 6.5, and 8.0, b. amyloliquefaciens alpha-amylase irreversibly inactivates due to a monomolecular conformational process, formation of incorrect (scrambled) structures which subsequently undergo aggregation. at the last ph, t ... | 1988 | 3257756 |
| new type of pullulanase from bacillus stearothermophilus and molecular cloning and expression of the gene in bacillus subtilis. | a new type of pullulanase which mainly produced panose from pullulan was found in bacillus stearothermophilus and purified. the enzyme can hydrolyze pullulan efficiently and only hydrolyzes a small amount of starch. when pullulan was used as a substrate, the main product was panose and small amounts of glucose and maltose were simultaneously produced. by using ptb522 as a vector plasmid, the enzyme gene was cloned and expressed in bacillus subtilis. since the enzyme from the recombinant plasmid ... | 1988 | 3127377 |
| the metabolism of aromatic ring fission products by bacillus stearothermophilus strain ic3. | bacillus stearothermophilus ic3 degraded the meta cleavage product of catechol, 2-hydroxymuconic semialdehyde, to pyruvate and acetaldehyde via the 4-oxalocrotonate pathway. the pathway was identical to those previously delineated in several mesophilic organisms. however, all the enzymes showed activity at 55 degrees c and other properties (substrate specificities and effects of metal ions) also differed from those displayed by the mesophilic enzymes. all enzymes of this meta cleavage pathway, e ... | 1988 | 3269389 |
| the evaluation of the recovery capacity of media for heat-treated bacillus stearothermophilus spore strips. | six media were assessed for their capacity to recover spores of bacillus stearothermophilus from three commercially available types of spore strip heated for up to 5 min at 121 degrees c in steam. all media recovered similar numbers of spores from unheated strips; however, there was considerable difference in survivor counts when the media were used to recover heated spores. media containing starch consistently recovered the highest number of spores. the greatest difference in recovery capacity ... | 1988 | 3275315 |
| spore tests verify sterilization. | | 1988 | 3134633 |
| sequence comparisons in the aminoacyl-trna synthetases with emphasis on regions of likely homology with sequences in the rossmann fold in the methionyl and tyrosyl enzymes. | amino acid sequences of aminoacyl-trna synthetases specific for 12 different amino acids have now been published. differences in origin at the species and organelle level result in 20 distinct sequences being available for comparison. some of these were compared in small groups as they were determined and, although some homologies were detected, it was generally concluded that there was surprisingly little sequence homology in this functionally related group of enzymes. we have made comparisons ... | 1988 | 3283733 |
| efficacy of various methods of sterilization of acupuncture needles. | the iatrogenic transmission of hepatitis b virus by inadequately sterilized acupuncture needles recently has been reported. because some licensed chiropractors use acupuncture as a therapeutic modality, we have evaluated sterilization methods for these needles, which would be adaptable for use in a chiropractic office. dry heat, boiling water, pressurized steam, sodium hypochlorite, and 70% alcohol were compared with a glass bead dry heat sterilizer originally developed for dental instruments. p ... | 1988 | 3290376 |
| [1h-nmr study of protein l7/l12 from bacterial ribosomes]. | the 500 mhz 1h-nmr spectra of dimeric protein l12 from ribosomes shows a limited number of unusually sharp signals at room temperature. this is interpreted as evidence for substantial segmental flexibility of the region in the protein molecule. we have analysed the extent of the flexible region and also the size of the organized structures of the molecule. thus residues 37-50 were found to be highly mobile whereas the n-terminal and c-terminal region are organized into folded domains. | 1988 | 3065618 |
| gene cloning and sequence determination of leucine dehydrogenase from bacillus stearothermophilus and structural comparison with other nad(p)+-dependent dehydrogenases. | the gene for leucine dehydrogenase (ec 1.4.1.9) from bacillus stearothermophilus was cloned and expressed in escherichia coli. the selection for the cloned gene was based upon activity staining of the replica printed e. coli cells. a transformant showing high leucine dehydrogenase activity was found to carry an about 9 kilobase pair plasmid, which contained 4.6 kilobase pairs of b. stearothermophilus dna. the nucleotide sequence including the 1287 base pair coding region of the leucine dehydroge ... | 1988 | 3069133 |
| [the significance of heat activation for the testing of bioindicators on surviving microorganisms exposed to formaldehyde]. | heat activation is a special phenomenon: after an additional heat treatment, a larger share of the bacterial spores which had been exposed to formaldehyde proves to be viable than without such heat activation. model studies have been performed to test the effects of heat activation on the examination of bioindicators and test objects for surviving organisms. test objects (cotton threads of 1 cm length) contaminated with spores of bacillus stearothermophilus were used for these trials. the test o ... | 1988 | 3138833 |
| the valyl-trna synthetase from bacillus stearothermophilus has considerable sequence homology with the isoleucyl-trna synthetase from escherichia coli. | we report the dna sequence of the vals gene from bacillus stearothermophilus and the predicted amino acid sequence of the valyl-trna synthetase encoded by the gene. the predicted primary structure is for a protein of 880 amino acids with a molecular mass of 102,036. the molecular mass and amino acid composition of the expressed enzyme are in close agreement with those values deduced from the dna sequence. comparison of the predicted protein sequence with known protein sequences revealed a consid ... | 1987 | 3300774 |
| synthesis of hybrid bisnucleoside 5',5"'-p1,p4-tetraphosphates by aminoacyl-trna synthetases. | aminoacyl trna synthetases, by means of a back reaction, are able to synthesize certain 5', 5"'-p1, p4-bisnucleoside tetraphosphates of biological importance, such as ap4a. here it is shown that hisrs and trprs (bacillus stearothermophilus) and alars (e. coli) also synthesize the hybrid compounds ap4g, ap4c, and ap4u. glnrs (e. coli) is unable to synthesize any of the above compounds. alars synthesizes ap4u very poorly, and ap4c and ap4g almost as effectively as ap4a. hisrs and trprs synthesize ... | 1987 | 3306344 |
| efficient synthesis and secretion of a thermophilic alpha-amylase by protein-producing bacillus brevis 47 carrying the bacillus stearothermophilus amylase gene. | bacillus subtilis and bacillus brevis 47-5, carrying the bacillus stearothermophilus alpha-amylase gene on pub110 (pbam101), synthesized the same alpha-amylase as the donor strain as determined by the enzyme's thermal stability and nh2-terminal amino acid sequence. regardless of the host, the 34-amino acid signal peptide of the enzyme was processed at exactly the same site between two alanine residues. b. brevis 47-5(pbam101) secreted the enzyme most efficiently of the hosts examined, 100, 15, a ... | 1985 | 2999073 |
| the specific modification of histidyl residues of inorganic pyrophosphatase from bacillus stearothermophilus by photooxidation. | photooxidation of inorganic pyrophosphatase [pyrophosphate phosphohydrolase ec 3.6.1.1] from bacillus stearothermophilus in the presence of rose bengal resulted in rapid loss of enzymatic activity. the ph profile of the inactivation rate by the photooxidation showed an inflection point around ph 6.8, suggesting the involvement of histidyl residues in the inactivation. amino acid analysis revealed that the loss of enzymatic activity was accompanied by the destruction of 3 histidyl residues per mo ... | 1985 | 2999092 |
| construction of a vector plasmid that can be maintained stably at higher temperatures in bacillus stearothermophilus and its application. | | 1987 | 3324870 |
| screening for thermostable mutant of kanamycin nucleotidyltransferase by the use of a transformation system for a thermophile, bacillus stearothermophilus. | a structural gene of kanamycin nucleotidyltransferase cloned into a single-stranded bacteriophage m13 was subjected to mutagenesis with hydroxylamine. having recloned the mutagenized gene of the enzyme in a vector plasmid ptb922, the recombinant plasmid was used to transform bacillus stearothermophilus with a purpose of screening for the more thermostable enzyme than the wild type. out of greater than 8 x 10(3) transformants, 12 clones that were suspected to harbor the mutant gene encoding the m ... | 1985 | 2999110 |
| approaches to the determination of the three-dimensional architecture of ribosomal particles. | | 1987 | 3331354 |
| two-dimensional crystalline sheets of bacillus stearothermophilus 50s ribosomal subunits containing a nascent polypeptide chain. | polylysine chains were synthesized on bacillus stearothermophilus ribosomes in a poly(a)-programmed in vitro system. after separation of the ribosomal subunits by sucrose gradient centrifugation, the polylysine chains (in contrast to the polyphenylalanine chains synthesized in a poly(u) system) reproducibly remained attached to the large ribosomal subunit. it was possible to produce two-dimensional crystalline sheets from the large ribosomal subunits containing the polylysine chains. these sheet ... | 1988 | 3139083 |
| nucleotide sequence and high-level expression of the major escherichia coli phosphofructokinase. | the gene for the major phosphofructokinase enzyme in escherichia coli, pfka, has been sequenced. comparison of the amino acid sequence with other phosphofructokinases showed that this enzyme is related to the bacillus stearothermophilus and rabbit muscle enzymes, but is different from the second, minor phosphofructokinase found in e. coli. the region which has been sequenced comprises the complete pfka--tpi interval on the e. coli genetic map. two other genes have been identified from the nucleo ... | 1985 | 3158524 |
| approaching the molecular structure of ribosomes. | fifteen forms of three-dimensional crystals and three forms of two-dimensional sheets from ribosomal particles have been grown. in all cases only biologically active particles could be crystallized, the crystalline material retaining its integrity and biological activity for months. cryastallographic data have been collected from crystals of 50 s ribosomal subunits, using synchrotron radiation, at temperatures between 19 and -180 degree c. although at around 0 degrees c in the synchrotron x-ray ... | 1988 | 3359000 |
| asymmetry of tyrosyl-trna synthetase in solution. | the tyrosyl-trna synthetase from bacillus stearothermophilus crystallizes as a symmetrical dimer with each subunit having a complete active site. the enzyme-substrate complexes, however, are known to be asymmetrical in solution because the enzyme exhibits half-of-the-sites activity by binding tightly only 1 mol of tyrosine or 1 mol of tyrosyl adenylate per mole of dimer. evidence is now presented that the unligated enzyme is also asymmetrical in solution. symmetry was investigated by constructio ... | 1988 | 3365365 |
| structure of a beta-galactosidase gene of bacillus stearothermophilus. | the nucleotide sequence of the bgab gene, which encodes the thermostable beta-galactosidase i of bacillus stearothermophilus, and its flanking region was determined. a 2,016-base-pair open reading frame observed was concluded to be for beta-galactosidase i (mr 78,051) from observations that the amino acid composition of the enzyme and the sequence of 14 amino acids from the amino-terminus of the enzyme coincided with those deduced from this open frame. a 107-base-pair haeiii-alui fragment just u ... | 1986 | 3086288 |
| determination of residual cephalexin in chick tissues by bacillus stearothermophilus paper disc assay. | a paper disc method is described for determination of residual cephalexin (cex) in chick tissues. a trichloroacetic acid extract of plasma and tissues is chromatographed on a macroreticular resin (diaion hp-20) column to remove endogenous antibacterial substances interfering with the assay. the eluate is evaporated to dryness and the residue, dissolved in methanol-water (1 + 2), is subjected to a paper disc assay using bacillus stearothermophilus var. calido-lactis c953 nizo as a test organism. ... | 1988 | 3384782 |
| structure and function of l-lactate dehydrogenases from thermophilic and mesophilic bacteria, iv. the primary structure of the mesophilic lactate dehydrogenase from bacillus subtilis. | the complete amino-acid sequence of lactate dehydrogenase from the mesophilic bacillus subtilis (b. x1) was determined. approximately 70% of the sequence was obtained by sequence analysis of intact protein (n-terminal sequence) and of four cnbr fragments (cnbr3, cnbr4, cnbr5 and cnbr6). sequences overlapping the cnbr fragments were determined from polypeptide fragments obtained by cleavage using o-iodosobenzoic acid (cleavage at trp) or clostripain (cleavage at arg). the c-terminal amino-acid re ... | 1986 | 3098260 |
| structure of a mutant of tyrosyl-trna synthetase with enhanced catalytic properties. | one surprising outcome of applying the techniques of protein engineering to the enzyme tyrosyl-transfer rna synthetase was that the enzyme's activity could actually be increased by a specific sequence change. in particular, altering residue threonine 51 to a proline (mutant tp51) increased the enzyme's affinity for tyrosyl adenylate complexes. the non-additive effect of combining the tp51 mutation with a second sequence alteration (histidine 48 to a glycine) suggested that the effect of the tp51 ... | 1987 | 3104791 |
| a new alcohol dehydrogenase, reactive towards methanol, from bacillus stearothermophilus. | an nad+-dependent alcohol dehydrogenase (adh) was purified to homogeneity from an aerobic strain of bacillus stearothermophilus, dsm 2334 (adh 2334), and compared with the adh from b. stearothermophilus nca 1503 (adh 1503). when an antibody raised against adh 2334 was used, no cross-reactivity with adh 1503 was observed on western blots; by means of an enzyme-linked-immunoabsorbent-assay ('e.l.i.s.a.') procedure, it was found that adh 1503 had less than 6% of the antigenic activity of adh 2334. ... | 1988 | 3421916 |
| a strong carboxylate-arginine interaction is important in substrate orientation and recognition in lactate dehydrogenase. | using site-directed mutagenesis, arginine-171 at the substrate-binding site of bacillus stearothermophilus, lactate dehydrogenase has been replaced by lysine. in the closely homologous eukaryotic lactate dehydrogenase, this residue binds the carboxylate group of the substrate by forming a planar bifurcated bond. the mutation diminishes the binding energy of pyruvate, alpha-ketobutyrate and alpha-ketovalerate (measured by kcat/km) by the same amount (about 6 kcal/mol). for each additional methyle ... | 1987 | 3113484 |
| an evaluation of three biological indicator systems in flash sterilization. | an evaluation of two flash-sterilization-specific biological indicators (bi) and a traditional spore strip indicator was performed to assess sensitivity and reliability as reflected in survive/kill ratios. the bis tested included: 3m's attest #1261, amsco's proof flash, and castle tec test. survival after "come-up" time alone, (0 exposure) and one-, two-, and three-minute exposures at 273 degrees f in a gravity displacement sterilizer was measured by media color change or turbidity after incubat ... | 1987 | 3115909 |
| epidermal growth factor receptor tyrosine kinase phosphorylation of glucose-6-phosphate dehydrogenase in vitro. | the specific tyrosine phosphorylation of glucose-6-phosphate dehydrogenase (g6pdh) by the epidermal growth factor (egf) receptor in vitro is demonstrated. the km values of the substrate g6pdh and of atp for the receptor tyrosine kinase were ca. 1 and 10 microm, respectively. the rate of phosphorylation was egf dependent, with a four-fold increase in vmax in the presence of egf. the phosphorylation was stimulated maximally by 0.2 microm or greater egf, with an ed50 of ca. 20 nm which is consisten ... | 1987 | 3122660 |
| identification of highly reactive cysteinyl and methionyl residues of rabbit muscle phosphofructokinase. | the reactivity of the 16 thiol groups of rabbit skeletal muscle phosphofructokinase has been studied extensively over the past 20 years. several of these thiols show high reactivity with a variety of reagents, display differential reactivity in the presence of allosteric ligands and substrates, and appear to be important to function because their modification changes activity and regulatory properties. in the present study, the location in the primary structure of several highly reactive thiol g ... | 1987 | 3038892 |
| relation of the heat resistance of bacterial spores to chemical composition and structure. ii. relation to cortex and structure. | the relation between the amount of cortex, measured as total hexosamine, as diaminopimelic acid and as muramic lactam, and the heat resistance of spores of five different strains of bacillus stearothermophilus was studied. electron micrographs of thin sections of the spores were made to relate the structure of the spores to chemical and thermal characteristics. it was found that the amount of the cortex was significantly related to heat resistance of the spores. strains with more electron-dense ... | 1987 | 3429356 |
| the growth of ordered two-dimensional sheets of ribosomal particles from salt-alcohol mixtures. | a procedure for the in vitro growth of well-ordered two-dimensional sheets from ribosomal particles using salts and salt-alcohol mixtures has been developed. employing this procedure, ordered two-dimensional sheets of the wild type as well as of mutated 50 s ribosomal subunits from bacillus stearothermophilus can readily be obtained. these sheets, stained with uranyl acetate or gold-thioglucose, are suitable for three-dimensional image reconstruction. they consist of relatively small unit cells ... | 1987 | 3434787 |
| three-dimensional crystals of ribosomes and their subunits from eu- and archaebacteria. | ordered three-dimensional crystals of 70s ribosomes as well as of 30s and 50s ribosomal subunits from various bacteria (e. coli, bacillus stearothermophilus, thermus thermophilus and halobacterium marismortui) have been grown by vapour diffusion in hanging drops using mono- and polyalcohols. a new compact crystal form of 50s subunits has been obtained, and it is suitable for crystallographic studies at medium resolution. in addition, from one crystal form large crystals could be grown in x-ray c ... | 1987 | 3124853 |
| investigation of transition-state stabilization by residues histidine-45 and threonine-40 in the tyrosyl-trna synthetase. | we have analyzed various mutations involving residues thr-40 and his-45 in the tyrosyl-trna synthetase of bacillus stearothermophilus. the utilization of binding energy in catalysis of tyrosyl adenylate formation from tyrosine and atp was determined from the free energy profiles for the mutant enzymes. our results confirm that the side chains of thr-40 and his-45 provide a binding site for the pyrophosphoryl portion of the transition state of this reaction and for pyrophosphate in the reverse re ... | 1987 | 3126804 |
| order of binding of substrate to valyl-trna synthetase from bacillus stearothermophilus in amino acid activation reaction. | amino acid activation reaction with valyl-trna synthetase (ec 6.1.1.9) from bacillus stearothermophilus was studied kinetically by measuring atp-ppi exchange to find the order of the binding of substrate to the enzyme. the effects of the concentration of the substrates (l-valine and atp) and two dead-end inhibitors (l-valinol and adenosine) on the reaction rate were analyzed. the results indicate that l-valine and atp are bound to the enzyme in a random sequence. this conclusion is consistent wi ... | 1987 | 3453086 |
| alpha-factor-directed synthesis of bacillus stearothermophilus alpha-amylase in saccharomyces cerevisiae. | promoter and leader sequence of bacillus stearothermophilus alpha-amylase gene were removed and the gene was joined in-frame to sequences encoding the leader region of saccharomyces cerevisiae mating pheromone alpha-factor on plasmid p69a (a hybrid of pbr322 and s. cerevisiae 2-microns plasmid). s. cerevisiae cells were transformed with plasmids containing the hybrid genes, obtaining yeast transformants which exhibit a significant extra-cellular amylolytic activity in solid medium, but not in li ... | 1988 | 3282514 |
| crystal structure of a prokaryotic ribosomal protein. | the structure of ribosomal protein l30 from bacillus stearothermophilus has been solved to a resolution of 2.5 a. the molecule is somewhat elongated and contains two helices and a three-stranded, anti-parallel beta-pleated sheet. the protein fold, in which helices pack on the same side of the sheet, generates a simple helix-sheet, two-layered motif. it is possible to distinguish three hydrophobic patches on the molecular surface, and one end has six isolated arginine and lysine residues. it is p ... | 1986 | 3463963 |
| racemization of alanine by the alanine racemases from salmonella typhimurium and bacillus stearothermophilus: energetic reaction profiles. | alanine racemases are bacterial pyridoxal 5'-phosphate (plp) dependent enzymes providing d-alanine as an essential building block for biosynthesis of the peptidoglycan layer of the cell wall. two isozymic alanine racemases, encoded by the dadb gene and the alr gene, from the gram-negative mesophilic salmonella typhimurium and one from the gram-positive thermophilic bacillus stearothermophilus have been examined for the racemization mechanism. substrate deuterium isotope effects and solvent deute ... | 1988 | 3291946 |
| cross-linked amino acids in the protein pair s13-s19 and sequence analysis of protein s13 of bacillus stearothermophilus ribosomes. | the 30s ribosomal subunits from bacillus stearothermophilus were cross-linked under native conditions with the bifunctional reagent diepoxybutane. the dominant protein-protein cross-link in the 30s ribosomal subunit between proteins s13 and s19 [brockmöller, j., & kamp, r.m. (1986) biol. chem. hoppe-seyler 367, 925-935] was isolated on a preparative scale. the presence of a single cross-link site between cysteine-83 of protein s13 and histidine-68 of protein s19 was established by microsequence ... | 1988 | 3291949 |
| amino acid sequence of the l-lactate dehydrogenase of bacillus caldotenax deduced from the nucleotide sequence of the cloned gene. | the bacillus caldotenax l-lactate dehydrogenase gene (lct) has been cloned into escherichia coli, using the bacillus stearothermophilus lct gene as a hybridisation probe, and its complete nucleotide sequence determined. the lct structural gene consists of an open reading frame of 951 base pairs commencing with an atg start codon and followed by a taa stop codon. upstream of the gene are putative transcriptional promoter -35 and -10 regions; a ribosome binding site with a predicted delta g of -66 ... | 1987 | 3297694 |
| effects of temperature on plasmid stability and penicillinase productivity of a transformant of bacillus stearothermophilus. | | 1986 | 3488008 |
| structural and spectroscopic comparison of manganese-containing superoxide dismutases. | predicted secondary structures and optical properties of four manganese-containing superoxide dismutases isolated from saccharomyces cerevisiae, bacillus stearothermophilus, escherichia coli and human liver are compared. the structural predictions are further compared with the known crystal structure of the manganese-containing superoxide dismutase from thermus thermophilus hb8. the secondary structures of the four dismutases are predicted by the methods of chou and fasman (adv. enzymol. 47 (197 ... | 1987 | 3307925 |
| rational construction of a 2-hydroxyacid dehydrogenase with new substrate specificity. | using site-directed mutagenesis on the lactate dehydrogenase gene from bacillus stearothermophilus, three amino acid substitutions have been made at sites in the enzyme which we suggest in part determine specificity toward different hydroxyacids (r-choh-cooh). to change the preferred substrates from the pyruvate/lactate pair (r = -ch3) to the oxaloacetate/malate pair (r = -ch2-coo-), the volume of the active site was increased (thr 246----gly), an acid was neutralized (asp-197----asn) and a base ... | 1987 | 3314868 |
| extracellular production of cloned alpha-amylase by escherichia coli. | overexpression of bacillus stearothermophilus gene coding for thermostable alpha-amylase in escherichia coli was shown to cause outer-membrane damage leading to extracellular location of periplasmic proteins. prolonged high expression of the alpha-amylase gene under laczpo control eventually also lysed cells. surprisingly, expression controlled by the pl promoter of phage lambda allowed specific release of periplasmic proteins into the growth medium without total cell lysis. accumulation of alph ... | 1987 | 3327755 |
| asparaginyl-rhamnose: a novel type of protein-carbohydrate linkage in a eubacterial surface-layer glycoprotein. | the subunits of the crystalline surface layer of bacillus stearothermophilus, strain nrs 2004/3a contain carbohydrates covalently linked to protein. hydrolysis of a glycopeptide obtained by pronase digestion of the glycoprotein and analysis of the fragments revealed that rhamnose is n-glycosidically linked to the amide nitrogen of an asparaginyl residue. | 1988 | 3342887 |
| crystal structure of manganese superoxide dismutase from bacillus stearothermophilus at 2.4 a resolution. | the crystal structure of manganese superoxide dismutase (mnsod) from bacillus stearothermophilus has been solved at 2.4 a resolution by a combination of multiple isomorphous replacement and molecular replacement (1 a = 0.1 nm). the structure has been refined to a conventional r-factor for all 16,560 unique reflections at 2.4 a of 0.26, and the 2fo-fc density maps show features more consistent with the known amino acid sequence of mnsod from b. stearothermophilus than with the starting model, the ... | 1988 | 3351946 |
| an investigation of the contribution made by the carboxylate group of an active site histidine-aspartate couple to binding and catalysis in lactate dehydrogenase. | the influence of aspartate-168 on the proton-donating and -accepting properties of histidine-195 (the active site acid/base catalyst in lactate dehydrogenase) was evaluated by use of site-directed mutagenesis to change the residue to asparagine and to alanine. despite the fact that asparagine could form a hydrogen bond to histidine while alanine could not, the two mutant enzymes have closely similar catalytic and ligand-binding properties. both bind pyruvate and its analogue (oxamate) 200 times ... | 1988 | 3365414 |
| inhibition of alanine racemase by alanine phosphonate: detection of an imine linkage to pyridoxal 5'-phosphate in the enzyme-inhibitor complex by solid-state 15n nuclear magnetic resonance. | inhibition of alanine racemase from the gram-positive bacterium bacillus stearothermophilus by (1-aminoethyl) phosphonic acid (ala-p) proceeds via a two-step reaction pathway in which reactivation occurs very slowly. in order to determine the mechanism of inhibition, we have recorded low-temperature, solid-state 15n nmr spectra from microcrystals of the [15n]ala-p-enzyme complex, together with spectra of a series of model compounds that provide the requisite database for the interpretation of th ... | 1988 | 3167024 |
| a transcription terminator in the 5' non-coding region of the tyrosyl trna synthetase gene from bacillus stearothermophilus. | the 5' non-coding region of the tyrosyl-trna synthetase gene (tyrs) of bacillus stearothermophilus is 324 nucleotides long. it contains a premature terminator and a strong promoter: these were identified in vitro by rna run-off experiments and in escherichia coli by construction of specific mutants. the terminator consists of a stem and loop structure followed by the string of t residues characteristic of rho-independent termination. this is preceded by another stem and loop structure which may ... | 1986 | 3525162 |
| localized insertion of new s-layer during growth of bacillus stearothermophilus strains. | bacillus stearothermophilus strains pv 72 and atcc 12980 carry a crystalline surface layer (s-layer) with hexagonal (p6) and oblique (p2) symmetry, respectively. sites of insertions of new subunits into the regular lattice during cell growth have been determined by the indirect fluorescent antibody technique and the protein a/colloidal gold technique. during s-layer growth on both bacillus strains the following common features were noted: 1. shedding of intact s-layer or turnover of individual s ... | 1988 | 3389970 |
| amino acid sequence analysis of the lipoyl and peripheral subunit-binding domains in the lipoate acetyltransferase component of the pyruvate dehydrogenase complex from bacillus stearothermophilus. | the pyruvate dehydrogenase multienzyme complex from bacillus stearothermophilus comprises a structural core, composed of 60 dihydrolipoamide acetyltransferase (e2p) subunits, which binds multiple copies of pyruvate decarboxylase (e1p) and dihydrolipoamide dehydrogenase (e3) subunits. after limited proteolysis with chymotrypsin, the n-terminal lipoyl domain of e2p was excised, purified and sequenced. the residual complex, which remained assembled, was then digested with trypsin under mild conditi ... | 1988 | 3421911 |
| tyrosyl-trna synthetase acts as an asymmetric dimer in charging trna. a rationale for half-of-the-sites activity. | tyrosyl-trna synthetase from bacillus stearothermophilus is a classical example of an enzyme with half-of-the-sites activity. the enzyme crystallizes as a symmetrical dimer that is composed of identical subunits, each having a complete active site. in solution, however, tyrosyl-trna synthetase binds tightly, and activates rapidly, only 1 mol of tyr/mol of dimer. it has recently been shown that the half-of-the-sites activity results from an inherent asymmetry of the enzyme. only one subunit catal ... | 1988 | 3179266 |
| effect of disc moistening method on bacillus stearothermophilus disc assay zone diameters. | effect of disc moistening method on the bacillus stearothermophilus disc assay zone size was studied. pasteurized homogenized milk was subdivided and three levels of us pharmacopeial reference standard penicillin g were added. disc assay filter paper discs were moistened using the standard capillary action procedure and a method incorporating the use of a 90-microliters micropipetter. amount of milk sample absorbed by discs prepared by the capillary action method was correlated with disc mass. v ... | 1988 | 3183141 |
| a dna-modification methylase from bacillus stearothermophilus v. | a type ii modification methylase (m bstvi) was partially purified from the thermophilic bacterium bacillus stearothermophilus v. the methylase catalyses the transfer of methyl groups from s-adenosyl-l-methionine to unmodified double-stranded dna. the product of methylation was identified by paper chromatography as n6-methyladenine. since m bstvi protects dna against cleavage by bstvi and xhoi restriction endonucleases, it follows that it methylates the adenine residue in the sequence 5'-c-t-c-g- ... | 1988 | 3202841 |
| thermostable peroxidase from bacillus stearothermophilus. | a peroxidase from bacillus stearothermophilus was purified to homogeneity. the enzyme (mr 175,000) was composed of two subunits of equal size, and showed a soret band at 406 nm. on reduction with sodium dithionite, absorption at 434 nm and 558 nm was observed. the spectrum of reduced pyridine haemochrome showed peaks at 418, 526 and 557 nm; the reduced minus oxidized spectrum of pyridine haemochrome showed peaks of 418, 524 and 556 nm with a trough at 452 nm. these results indicate that the enzy ... | 1988 | 3246591 |
| microbial receptor assay for rapid detection and identification of seven families of antimicrobial drugs in milk: collaborative study. | a microbial competitive receptor assay for detecting residues of antibiotic families in milk was studied collaboratively by 13 laboratories. the drugs and levels (ppb) tested in this study include penicillin g, 4.8; cephapirin, 5.0; cloxacillin, 100; tetracycline, 2000; chlortetracycline, 2000; oxytetracycline, 2000; erythromycin, 200; lincomycin, 400; clindamycin, 400; sulfamethazine, 75; sulfamethoxazole, 50; sulfisoxazole, 50; streptomycin, 1000; novobiocin, 50; and chloramphenicol, 800. in t ... | 1988 | 3260233 |
| the use of genetically engineered tryptophan to identify the movement of a domain of b. stearothermophilus lactate dehydrogenase with the process which limits the steady-state turnover of the enzyme. | a general technique for monitoring the intramolecular motion of a protein is described. genetic engineering is used to replace all the natural tryptophan residues with tyrosine. a single tryptophan residue is then inserted at a specific site within the protein where motion is then detected from the fluorescence characteristics of this fluorophore. this technique has been used in b. stearothermophilus lactate dehydrogenase mutant (w80y, w150y, w203y, g106w) to correlate the slow closure of a surf ... | 1988 | 3422557 |
| site-directed mutagenesis reveals transition-state stabilization as a general catalytic mechanism for aminoacyl-trna synthetases. | some aminoacyl-trna synthetases of almost negligible homology do have a small region of similarity around four-residue sequence his-ile(or leu or met)-gly-his(or asn), the high sequence. the first histidine in this sequence in the tyrosyl-trna synthetase, his-45, has been shown to form part of a binding site for the gamma-phosphate of atp in the transition state for the reaction as does thr-40. residue his-56 in the valyl-trna synthetase begins a high sequence, and there is a threonine at positi ... | 1987 | 3427072 |
| isolation and structure determination of a diacetamidodideoxyuronic acid-containing glycan chain from the s-layer glycoprotein of bacillus stearothermophilus nrs 2004/3a. | a glycan isolated from the surface-layer glycoprotein of bacillus stearothermophilus strain nrs 2004/3a was shown by 1h- and 13c-n.m.r. spectroscopy to have the tetrasaccharide repeating-unit ----4)-beta-manpa2,3(nac)2-(1----3)-alpha-glcpnac-(1----4)-beta- manpa2,3(nac)-(1----6)-alpha-glcp(1----. | 1987 | 3427581 |
| the active site of manganese-containing superoxide dismutase from bacillus stearothermophilus studied by 1h and 19f magnetic relaxation. | the dependence of the magnetic relaxation rates of 1h and 19f- on temperature, frequency, ph and n-3 concentration, were measured in solutions of manganese-containing superoxide dismutase of bacillus stearothermophilus, and were compared to activity measurements, in order to obtain some information on the structure and dynamics at mn(iii) present in the active site of the enzyme. the experimental data lead us to hypothesize the presence of two binding sites in the coordination sphere of the enzy ... | 1987 | 3428245 |
| reconstitution and crystallisation experiments with isolated split proteins from bacillus stearothermophilus ribosomes. | six proteins (b-l1, b-l6, b-l10, b-l11, b-l12 and b-l16) were removed from 50s ribosomal subunits of bacillus stearothermophilus by treatment with ethanol and ammonium chloride. the proteins were isolated in a pure form, and one of them (b-l6) was crystallized. five of the six proteins (in various combinations) were added back to the core particles, resulting in 50s subunits lacking one protein. the biological activities of these ribosomal particles as determined in the poly(u)-system varied ove ... | 1987 | 3435552 |
| dissection of the structure and activity of the tyrosyl-trna synthetase by site-directed mutagenesis. | to understand an enzyme reaction, one has to characterize the bound substrates, intermediates, products, and transition states on the reaction pathway and determine the interaction energies between them and the enzyme as the reaction proceeds. site-directed mutagenesis is invaluable in this task, enabling the systematic dissection of the active site. residues involved in catalysis may be detected and the energetics probed. the contributions of each hydrogen-bonding site chain in the active site ... | 1987 | 3442641 |
| characterization of the ultrastructure and the self-assembly of the surface layer of bacillus stearothermophilus strain nrs 2004/3a. | the ultrastructure of the crystalline surface layer (s-layer) of bacillus stearothermophilus strain nrs 2004/3a has been characterized by electron microscopy supplemented by optical and computer image analysis. the s-layer, composed of glycoprotein subunits, has oblique symmetry, and can be extracted by guanidine hydrochloride. upon dialysis, this extract produced both flat and cylindrical mono- and double-layer self-assembly products. optical diffraction analysis of negatively stained preparati ... | 1986 | 3453374 |
| free energy of hydrolysis of tyrosyl adenylate and its binding to wild-type and engineered mutant tyrosyl-trna synthetases. | the equilibrium constant for the formation of tyrosyl adenylate and pyrophosphate from atp and tyrosine in solution has been measured by applying the haldane relationship to wild-type and three mutant tyrosyl-trna synthetases from bacillus stearothermophilus. the formation constant (=[tyr-amp] [ppi]/[atp] [tyr]) at ph 7.78, 25 degrees c, and 10 mm mgcl2 is (3.5 +/- 0.5) x 10(-7). this corresponds to a free energy of hydrolysis of tyrosyl adenylate at ph 7.0 and 25 degrees c of -16.7 kcal mol-1. ... | 1986 | 3466647 |
| structure-activity relationships in engineered proteins: analysis of use of binding energy by linear free energy relationships. | the activity of mutant enzymes can be analyzed quantitatively by structure-activity relationships in a manner analogous to brønsted or hammett plots for simple organic reactions. the slopes of such plots, the beta values, indicate for the enzymatic reactions the fraction of the overall binding energy used in stabilizing particular complexes. in particular, information can be derived about the interactions between the enzyme and the transition state. the activities of many mutant tyrosyl-trna syn ... | 1987 | 3480005 |
| structure-activity relationships in engineered proteins: characterization of disruptive deletions in the alpha-ammonium group binding site of tyrosyl-trna synthetase. | residues asp-78 and gln-173 of the tyrosyl-trna synthetase of bacillus stearothermophilus form part of the binding site for tyrosine by making hydrogen bonds with the alpha-ammonium group. asp-38 is close enough to the group to make an important electrostatic contribution. unlike other residues in the active site that have been studied by site-directed mutagenesis, asp-38, asp-78, and gln-173 are part of hydrogen-bonded networks. each of these residues has been mutated to an alanine, and the res ... | 1987 | 3480006 |
| initial-rate studies of a thermophilic glucokinase from bacillus stearothermophilus. | the initial rates of phosphorylation of glucose catalysed by glucokinase from bacillus stearothermophilus were measured over a wide range of glucose, mgatp2-, mgadp- and glucose 6-phosphate concentrations. the results of the effects of the inhibitors on the initial rates suggest that the reaction mechanism is essentially the ordered bi bi, in which glucose adds to the enzyme before mgatp2- and glucose 6-phosphate is released from the enzyme after the dissociation of mgadp-, and also suggest that ... | 1987 | 3501715 |
| [extracellular thermostable alpha-amylase from bacillus stearothermophilus q8]. | the alpha-amylase of bacillus stearothermophilus q8, previously isolated in our laboratory, was purified by ammonium sulfate precipitation and cm-sephadex chromatography. the activity the of partial purified alpha-amylase was to be protected by bovine serum albumin ca2+ and mg2+. the enzyme showed 100% activity at ph 9.0; 98%, at ph 8.0 and 41%; at ph 10.0. it expressed optimal reaction temperature at 90 degrees c, 81% of the activities remained at 100 degrees c. after 15 min incubation at 100 d ... | 1987 | 3502403 |
| a novel method for the synthesis of kyotorphin, tyr-arg, and 3h-tyr-arg, catalyzed by tyrosyl-trna synthetase from bacillus stearothermophilus. | a novel method of dipeptide synthesis is described that can be carried out in aqueous solution and does not require complicated protecting and deprotecting procedures. an analgesic neuropeptide named kyotorphin, h-tyr-arg-oh, was synthesized from unprotected tyrosine and arginine in a new enzymatic reaction catalyzed by immobilized tyrosyl-trna synthetase from bacillus stearothermophilus. the reaction could be a useful tool in the syntheses of radioisotope-labeled oligopeptides to be used in rec ... | 1987 | 3509140 |
| structural homology between elongation factors ef-tu from bacillus stearothermophilus and escherichia coli in the binding site for aminoacyl-trna. | elongation factor ef-tu (mr approximately equal to 50 000) and elongation factor ef-g (mr approximately equal to 78 000) were isolated from bacillus stearothermophilus in a homogeneous form. the ability of ef-tu to participate in protein synthesis is rapidly inactivated by n-tosyl-l-phenyl-alanylchloromethane (tos-phech2cl). ef-tu x gtp is more susceptible to the inhibition by tos-phech2cl than is ef-tu x gdp. tos-phech2cl forms a covalent equimolar complex with the factor by reacting with a cys ... | 1986 | 3510872 |
| genetic analysis of bacillus stearothermophilus by protoplast fusion. | efficient and reliable protoplasting, regeneration, and fusion techniques were established for the prototrophic strain bacillus stearothermophilus nub36. auxotrophic mutants were isolated, and protoplast fusion was used to construct isogenic mutant strains and for chromosomal mapping. markers were mapped using two-, three-, and four-factor crosses. the order of the markers was hom-1-thr-1-his-1-(gly-1 or gly-2)-pur-1-pur-2. these markers may be analogous to hom, thra, hisa, glyc, and pura marker ... | 1986 | 3512533 |
| internal thermodynamics of position 51 mutants and natural variants of tyrosyl-trna synthetase. | natural variation and evolution impose structural changes on an enzyme that can affect the energetics of catalysis. the energy profile of reaction could, in theory, be altered in three distinct ways: uniform binding changes, differential binding changes, and catalysis of elementary steps. residue threonine-51 of tyrosyl-trna synthetase from bacillus stearothermophilus is subject to natural variation, being replaced by alanine and proline in the enzymes from bacillus caldotenax and escherichia co ... | 1986 | 3518795 |
| [nucleotide composition and the level of dna homology in a number of bacillus diasticus strains]. | the base composition of dna and dna homology of a number of strains bacillus diastaticus differing in the intensity of the amilase synthesis and some phenotipic properties have been studied. the differences in the base composition of dna have not been found. all stains studied are characterized by the high rate of dna homology. b. diastaticus and b. stearothermophilus have been established to be genetically similar. | 1986 | 3518816 |
| phospholipid surface bilayers at the air-water interface. iii. relation between surface bilayer formation and lipid bilayer assembly in cell membranes. | lipid bilayer assembly in cell membranes has been simulated with total lipid extracts from human red blood cells and from mesophilic and thermophilic bacteria grown at several temperatures. aqueous dispersions of these natural lipid mixtures form surface bilayers, a single bimolecular lipid state, but only at the growth temperature of the source organism. thus, a single isolated bilayer state forms spontaneously in vitro from lipids that are available in vivo at the growth temperature of the cel ... | 1986 | 3530344 |
| mechanism of translational initiation in prokaryotes. evidence for a direct effect of if2 on the activity of the 30 s ribosomal subunit. | initiation factor if2 from either escherichia coli or bacillus stearothermophilus was found to possess the previously undetected property of stimulating the template-dependent ribosomal binding of aminoacyl-trnas with free alpha-nh2 groups. if1, which had no detectable activity alone, was found to stimulate the activity of e. coli if2 and, to a lesser extent, that of b. stearothermophilus if2. since in the absence of ribosomes not even a weak interaction between the two if2 molecules and the ami ... | 1986 | 3533628 |
| the complete amino acid sequences of the 5 s rrna binding proteins l5 and l18 from the moderate thermophile bacillus stearothermophilus ribosome. | the complete amino acid sequences of the 5 s rrna binding proteins l5 and l18 isolated from ribosomes of the moderate thermophile bacillus stearothermophilus are presented. this has been achieved by the sequence analysis of peptides derived by enzymatic digestions with trypsin, chymotrypsin, pepsin, and staphylococcus aureus protease, as well as by chemical cleavage with cyanogen bromide. the proteins l5 and l18 consist of 179 and 120 amino acid residues, and have mr values of 20,163 and 13,473, ... | 1987 | 3542562 |
| the complete amino acid sequence of ribosomal protein s12 from bacillus stearothermophilus. | the amino acid sequence of ribosomal protein s12 from bacillus stearothermophilus has been completely determined. the sequence data were mainly obtained by manual sequencing of peptides derived from digestion with trypsin, staphylococcus aureas protease and pepsin. a few overlaps of tryptic peptides were established by dna sequence analysis of a chromosomal fragment containing the rpsl gene coding for ribosomal protein s12. the protein contains 138 amino acid residues and has an mr of 15,208. co ... | 1987 | 3542563 |
| conformation of b. stearothermophilus 5s ribosomal rna. | the thermal melting of b. stearothermophilus 5s ribosomal rna was studied, by means of derivative optical absorption and cd spectra, and high performance liquid chromatography, in tris buffers with k+ and mg2+ at ph 7.6. biphasic changes in optical absorption and cd ellipticity were observed, which mean the melting of two helices. change in molecular size was also examined in the melting process. the melting temperatures depended on ionic strength and concentration of mg2+. enhanced stability of ... | 1986 | 3562267 |
| thermal inactivation and injury of bacillus stearothermophilus spores. | aqueous spore suspensions of bacillus stearothermophilus atcc 12980 were heated at different temperatures for various time intervals in a resistometer, spread plated on antibiotic assay medium supplemented with 0.1% soluble starch without (aams) or with (aams-s) 0.9% nacl, and incubated at 55 degrees c unless otherwise indicated. uninjured spores formed colonies on aams and aams-s; injured spores formed colonies only on aams. values of d, the decimal reduction time (time required at a given temp ... | 1987 | 3566270 |
| a tunnel in the large ribosomal subunit revealed by three-dimensional image reconstruction. | a better understanding of the molecular mechanism of protein biosynthesis depends on the availability of a reliable model for the ribosome particle. the application of a diffraction technique, namely, three-dimensional image reconstruction from two-dimensional sheets of the large ribosomal subunits of bacillus stearothermophilus at a resolution of 30 angstroms is described. the resulting three-dimensional model shows at least four projecting arms, arranged radially near the presumed interface wi ... | 1987 | 3576200 |
| the use of site-directed mutagenesis and time-resolved fluorescence spectroscopy to assign the fluorescence contributions of individual tryptophan residues in bacillus stearothermophilus lactate dehydrogenase. | site-directed mutagenesis has been used to generate two mutant bacillus stearothermophilus lactate dehydrogenases: in one, trp-150 has been replaced with a tyrosine residue and, in the other, both trp-150 and -80 are replaced with tyrosines. both enzymes are fully catalytically active and their affinities for substrates and coenzymes, and thermal stabilities are very similar to those of the native enzyme. time-resolved fluorescence measurements using a synchrotron source have shown that all thre ... | 1987 | 3580376 |
| a single amino acid substitution deregulates a bacterial lactate dehydrogenase and stabilizes its tetrameric structure. | we have engineered a variant of the lactate dehydrogenase enzyme from bacillus stearothermophilus in which arginine-173 at the proposed regulatory site has been replaced by glutamine. like the wild-type enzyme, this mutant undergoes a reversible, protein-concentration-dependent subunit assembly, from dimer to tetramer. however, the mutant tetramer is much more stable (by a factor of 400) than the wild type and is destabilized rather than stabilized by binding the allosteric regulator, fructose 1 ... | 1987 | 3580377 |
| charge distribution on the s layer of bacillus stearothermophilus nrs 1536/3c and importance of charged groups for morphogenesis and function. | the distribution and functional significance of charged groups on the outer and inner faces of the s layer from bacillus stearothermophilus nrs 1536/3c was investigated. chemical modification of the exposed amino or carboxyl groups was performed on whole cells, isolated s layers self-assembled in vitro, and cell wall fragments (s layer attached to the peptidoglycan-containing sacculus). without chemical modification, s layer self-assembly products could be labeled with polycationic ferritin, whi ... | 1987 | 3584071 |
| fluorometric study on the interaction of amino acids and atp with valyl-trna synthetase from bacillus stearothermophilus. | interactions of several amino acids and nucleotides with valyl-trna synthetase [ec 6.1.1.9] (vrs) from bacillus stearothermophilus were investigated using as a probe the ligand-induced quenching of protein fluorescence (lambda ex = 295 nm, lambda em = 340 nm) of vrs. l-valine, l-threonine, l-isoleucine, l-glutamic acid, l-leucine, and d-valine caused fluorescence quenching. among them, l-threonine had a kd value comparable to that for the cognate substrate, l-valine, but the other amino acids we ... | 1987 | 3584095 |
| structure of holo-glyceraldehyde-3-phosphate dehydrogenase from bacillus stearothermophilus at 1.8 a resolution. | the structure of holo-glyceraldehyde-3-phosphate dehydrogenase from bacillus stearothermophilus has been crystallographically refined at 1.8 a resolution using restrained least-squares refinement methods. the final crystallographic r-factor for 93,120 reflexions with f greater than 3 sigma (f) is 0.177. the asymmetric unit of the crystal contains a complete tetramer, the final model of which incorporates a total of 10,272 unique protein and coenzyme atoms together with 677 bound solvent molecule ... | 1987 | 3586018 |