| toxicity of n-containing heterocyclic aromatic compounds and their utilization for growth by a few purple non-sulfur bacteria. | | 2000 | 10903362 |
| quinone-binding sites in membrane proteins: what can we learn from the rhodopseudomonas viridis reaction centre? | | 1999 | 10917648 |
| conformational relaxation following reduction of the photoactive bacteriopheophytin in reaction centers from balstochloris viridis. influence of mutations at position m208. | the photochemically trapped bacteriopheophytin (bph) b radical anion in the active branch (phi(*-)a) of reaction centers (rcs) from blastochloris (formerly called rhodopseudomonas) viridis is characterized by 1h-endor as well as optical absorption spectroscopy. the two site-directed mutants yf(m208) and yl(m208), in which tyrosine at position m208 is replaced by phenylalanine and leucine, respectively, are investigated and compared with the wild type. the residue at m208 is in close proximity to ... | 2000 | 10924911 |
| rnase iii processing of intervening sequences found in helix 9 of 23s rrna in the alpha subclass of proteobacteria. | we provide experimental evidence for rnase iii-dependent processing in helix 9 of the 23s rrna as a general feature of many species in the alpha subclass of proteobacteria (alpha-proteobacteria). we investigated 12 rhodobacter, rhizobium, sinorhizobium, rhodopseudomonas, and bartonella strains. the processed region is characterized by the presence of intervening sequences (ivss). the 23s rdna sequences between positions 109 and 205 (escherichia coli numbering) were determined, and potential seco ... | 2000 | 10940010 |
| electron transfer between the quinones in the photosynthetic reaction center and its coupling to conformational changes. | the electron transfer between the two quinones q(a) and q(b) in the bacterial photosynthetic reaction center (brc) is coupled to a conformational rearrangement. recently, the x-ray structures of the dark-adapted and light-exposed brc from rhodobacter sphaeroides were solved, and the conformational changes were characterized structurally. we computed the reaction free energy for the electron transfer from to q(b) in the x-ray structures of the dark-adapted and light-exposed brc from rb. sphaeroid ... | 2000 | 10956039 |
| femtosecond dynamics of the forbidden carotenoid s1 state in light-harvesting complexes of purple bacteria observed after two-photon excitation. | time-resolved excited-state absorption intensities after direct two-photon excitation of the carotenoid s(1) state are reported for light-harvesting complexes of purple bacteria. direct excitation of the carotenoid s(1) state enables the measurement of subsequent dynamics on a fs time scale without interference from higher excited states, such as the optically allowed s(2) state or the recently discovered dark state situated between s(1) and s(2). the lifetimes of the carotenoid s(1) states in t ... | 2000 | 10984512 |
| conformational relaxation following reduction of the photoactive bacteriopheophytin in reaction centers from blastochloris viridis. influence of mutations at position m208. | the photochemically trapped bacteriopheophytin (bph) b radical anion in the active branch (phi(a)(&z.rad;-)) of reaction centers (rcs) from blastochloris (formerly called rhodopseudomonas) viridis is characterized by 1h-endor as well as optical absorption spectroscopy. the two site-directed mutants yf(m208) and yl(m208), in which tyrosine at position m208 is replaced by phenylalanine and leucine, respectively, are investigated and compared with the wild type. the residue at m208 is in close prox ... | 2000 | 11004434 |
| re-emerging structures: continuing crystallography of the bacterial reaction centre. | the reaction centre is nature's solar battery, and is found in a number of variations on a common theme in plants, algae and photosynthetic bacteria. during the last 20 years, a combination of x-ray crystallography, spectroscopy and mutagenesis has provided increasingly detailed insights into the mechanism of light energy transduction in the bacterial reaction centre. this mini-review looks at the application of x-ray crystallography to the bacterial reaction centre, focussing in particular on r ... | 2000 | 11004458 |
| structural basis of the drastically increased initial electron transfer rate in the reaction center from a rhodopseudomonas viridis mutant described at 2.00-a resolution. | it has previously been shown that replacement of the residue his l168 with phe (hl168f) in the rhodopseudomonas viridis reaction center (rc) leads to an unprecedented drastic acceleration of the initial electron transfer rate. here we describe the determination of the x-ray crystal structure at 2.00-a resolution of the hl168f rc. the electron density maps confirm that a hydrogen bond from the protein to the special pair is removed by this mutation. compared with the wild-type rc, the acceptor of ... | 2000 | 11005826 |
| amino acid-specific isotopic labeling and active site nmr studies of iron(ii)- and iron(iii)-superoxide dismutase from escherichia coli. | we have developed and employed multiple amino acid-specific isotopic labeling schemes to obtain definitive assignments for active site 1h nmr resonances of iron(ii)- and iron(iii)-superoxide dismutase (fe(ii)sod and fe(iii)sod) from escherichia coli. despite the severe relaxivity of high-spin fe(iii), we have been able to assign resonances to ligand his' delta1 protons near 100 ppm, and beta and alpha protons collectively between 20 and 50 ppm, in fe(iii)sod. in the reduced state, we have assign ... | 2000 | 11014595 |
| pigment-protein architecture in the light-harvesting antenna complexes of purple bacteria: does the crystal structure reflect the native pigment-protein arrangement? | structural analysis of crystallized peripheral (lh2) and core antenna complexes (lh1) of purple bacteria has revealed circular aggregates of high rotational symmetry (c8, c9 and c16, respectively). quantum-chemical calculations indicate that in particular the waterwheel-like arrangements of pigments should show characteristic structure-sensitive spectroscopic behavior in the near infrared absorption region. laser-spectroscopic data obtained with non-crystallized, isolated lh2 of rhodospirillum m ... | 2000 | 11034303 |
| efficient exchange of the primary quinone acceptor q(a) in isolated reaction centers of rhodopseudomonas viridis. | a key step in the conversion of solar energy into chemical energy by photosynthetic reaction centers (rcs) occurs at the level of the two quinones, q(a) and q(b), where electron transfer couples to proton transfer. a great deal of our understanding of the mechanisms of these coupled reactions relies on the seminal work of okamura et al. [okamura, m. y., isaacson, r. a., & feher, g. (1975) proc. natl. acad. sci. usa 88, 3491-3495], who were able to extract with detergents the firmly bound ubiquin ... | 1997 | 11038584 |
| a periplasmic, alpha-type carbonic anhydrase from rhodopseudomonas palustris is essential for bicarbonate uptake. | intact cells of the purple non-sulfur bacterium rhodopseudomonas palustris growing anaerobically, but not aerobically, contain carbonic anhydrase (ca) activity. the native enzyme was purified >2000-fold to apparent homogeneity and found to be a dimer with an estimated molecular mass of 54 kda and a subunit molecular mass of 27 kda. the ca gene (acap) was cloned and its sequence revealed that it was homologous to alpha-type cas. the upstream region of acap was fused to the lacz gene and beta-gala ... | 2000 | 11065374 |
| crystallization and preliminary x-ray analysis of two ph-dependent forms of cytochrome c2 from rhodopseudomonas palustris. | cytochrome c(2) from rhodopseudomonas palustris has been crystallized in two different crystal forms: a monoclinic form i at ph 4.4 from both reduced and oxidized protein solution and a trigonal form ii at ph 9.0 from reduced protein solution. complete 1. 7 and 1.4 a resolution data sets were collected from the oxidized form i and from the form ii, respectively. the preliminary structures show an important change in the iron coordination environment in the trigonal form obtained at basic ph aris ... | 2000 | 11092951 |
| divergent mechanisms of 5' 23s rrna ivs processing in the alpha-proteobacteria. | widespread occurrence of a separate small rna derived from the 5'-end of 23s rrna and of an intervening sequence (ivs) which separates this domain from the main segment of 23s rrna in the alpha-proteobacteria implies that processing reactions which act to excise the ivs are also maintained in this group. we previously characterized the first example of processing of this ivs in rhodopseudomonas palustris, which is classified with the bradyrhizobia in this case, ivs excision occurs by a multistep ... | 2000 | 11095671 |
| how carotenoids protect bacterial photosynthesis. | the essential function of carotenoids in photosynthesis is to act as photoprotective agents, preventing chlorophylls and bacteriochlorophylls from sensitizing harmful photodestructive reactions in the presence of oxygen. based upon recent structural studies on reaction centres and antenna complexes from purple photosynthetic bacteria, the detailed organization of the carotenoids is described. then with specific reference to bacterial antenna complexes the details of the photoprotective role, tri ... | 2000 | 11127989 |
| efficient energy transfer from the carotenoid s(2) state in a photosynthetic light-harvesting complex. | previously, the spatial arrangement of the carotenoid and bacteriochlorophyll molecules in the peripheral light-harvesting (lh2) complex from rhodopseudomonas acidophila strain 10050 has been determined at high resolution. here, we have time resolved the energy transfer steps that occur between the carotenoid's initial excited state and the lowest energy group of bacteriochlorophyll molecules in lh2. these kinetic data, together with the existing structural information, lay the foundation for un ... | 2001 | 11159459 |
| acetate as a carbon source for hydrogen production by photosynthetic bacteria. | hydrogen is a clean energy alternative to fossil fuels. photosynthetic bacteria produce hydrogen from organic compounds by an anaerobic light-dependent electron transfer process. in the present study hydrogen production by three photosynthetic bacterial strains (rhodopseudomonas sp., rhodopseudomonas palustris and a non-identified strain), from four different short-chain organic acids (lactate, malate, acetate and butyrate) was investigated. the effect of light intensity on hydrogen production w ... | 2001 | 11164959 |
| reaction centres of purple bacteria. | the bacterial reaction centre is undoubtedly one of the most heavily studied electron transfer proteins and, as this article has tried to describe, it has made some unique contributions to our understanding of biological electron transfer and coupled protonation reactions, and has provided fascinating information in areas that concern basic properties such as protein heterogeneity and protein dynamics. despite intensive study, much remains to be learned about how this protein catalyses the conve ... | 2000 | 11192735 |
| phylogenetic and dna-dna hybridization analyses of bradyrhizobium species. | the 16s rdna sequence of bradyrhizobium liaoningense was determined and analysed together with sequences of other bradyrhizobium species and related taxa. in addition, dna-dna hybridizations were performed between representative strains of the three bradyrhizobium species. bradyrhizobium liaoningense is genotypically highly related to bradyrhizobium japonicum, whereas bradyrhizobium elkanii is more distantly related to these two species. the fact that afipia, agromonas, blastobacter, nitrobacter ... | 2001 | 11211247 |
| acute toxicity of las homologues in marine microalgae: esterase activity and inhibition growth as endpoints of toxicity. | the toxicity of two linear alkylbenzene sulfonate (las) homologues (c(10) and c(13)) was evaluated in four marine microalgae (nannochloropsis gaditana, tetraselmis suecica, rhodomonas salina, and isocrysis galbana), using growth inhibition rate and esterase activity (measured by flow cytometry) as endpoints. the inhibitor effect was higher for the c(13) las homologue than for c(11), in both responses analyzed. when both endpoints were compared, the growth inhibition rate was between 2 and 5 time ... | 2001 | 11222038 |
| photosynthetic electron transfer controlled by protein relaxation: analysis by langevin stochastic approach. | relaxation processes in proteins range in time from picoseconds to seconds. correspondingly, biological electron transfer (et) could be controlled by slow protein relaxation. we used the langevin stochastic approach to describe this type of et dynamics. two different types of kinetic behavior were revealed, namely: oscillating et (that could occur at picoseconds) and monotonically relaxing et. on a longer time scale, the et dynamics can include two different kinetic components. the faster one re ... | 2001 | 11222272 |
| statistical thermodynamics of membrane bending-mediated protein-protein attractions. | highly wedge-shaped integral membrane proteins, or membrane-adsorbed proteins can induce long-ranged deformations. the strain in the surrounding bilayer creates relatively long-ranged forces that contribute to interactions with nearby proteins. in contrast, to direct short-ranged interactions such as van der waal's, hydrophobic, or electrostatic interactions, both local membrane gaussian curvature and protein ellipticity can induce forces acting at distances of up to a few times their typical ra ... | 2001 | 11222274 |
| is there a conserved interaction between cardiolipin and the type ii bacterial reaction center? | in a recent publication, the structural details of an interaction between the rhodobacter sphaeroides reaction center and the anionic phospholipid diphosphatidyl glycerol (cardiolipin) were described (k. e. mcauley, p. k. fyfe, j. p. ridge, n. w. isaacs, r. j. cogdell, and m. r. jones, 1999, proc. natl. acad. sci. u.s.a. 96:14706-14711). this was the first crystallographic description of an interaction between this biologically important lipid and an integral membrane protein and was also the fi ... | 2001 | 11222300 |
| spectroscopy on the b850 band of individual light-harvesting 2 complexes of rhodopseudomonas acidophila. i. experiments and monte carlo simulations. | the electronic structure of the circular aggregate of 18 bacteriochlorophyll a (bchl a) molecules responsible for the b850 absorption band of the light-harvesting 2 (lh2) complex of the photosynthetic purple bacterium rhodopseudomonas acidophila has been studied by measuring fluorescence-excitation spectra of individual complexes at 1.2 k. the spectra reveal several well-resolved bands that are obscured in the single, broad b850 band observed in conventional absorption measurements on bulk sampl ... | 2001 | 11222320 |
| spectroscopy on the b850 band of individual light-harvesting 2 complexes of rhodopseudomonas acidophila. ii. exciton states of an elliptically deformed ring aggregate. | spectroscopy of individual light-harvesting 2 complexes from purple photosynthetic bacteria revealed a deformation of the circular complex into c(2) symmetry. the present work relates the geometry of the deformed aggregate to its spectroscopic properties. different models of elliptical deformation are discussed and compared with the experimental findings. it is shown that the model with smaller interpigment distances, where the curvature of the ellipse is small, provides the best agreement with ... | 2001 | 11222321 |
| probing the binding sites of exchanged chlorophyll a in lh2 by raman and site-selection fluorescence spectroscopies. | in this work we have selectively released the 800 nm absorbing bacteriochlorophyll a molecules of the lh2 protein from the photosynthetic bacterium rhodopseudomonas acidophila, strain 10050, and replaced them with chlorophyll a (chla). a combination of low-temperature electronic absorption, resonance raman and site-selection fluorescence spectroscopies revealed that the chla pigments are indeed bound in the b800 binding site; this is the first work that formally proves that such non-native chlor ... | 2001 | 11226437 |
| reductive, coenzyme a-mediated pathway for 3-chlorobenzoate degradation in the phototrophic bacterium rhodopseudomonas palustris. | we isolated a strain of rhodopseudomonas palustris (rcb100) by selective enrichment in light on 3-chlorobenzoate to investigate the steps that it uses to accomplish anaerobic dechlorination. analyses of metabolite pools as well as enzyme assays suggest that r. palustris grows on 3-chlorobenzoate by (i) converting it to 3-chlorobenzoyl coenzyme a (3-chlorobenzoyl-coa), (ii) reductively dehalogenating 3-chlorobenzoyl-coa to benzoyl-coa, and (iii) degrading benzoyl-coa to acetyl-coa and carbon diox ... | 2001 | 11229940 |
| novel methylated triterpenoids of the gammacerane series from the nitrogen-fixing bacterium bradyrhizobium japonicum usda 110. | the nitrogen-fixing, symbiotic root-nodule forming bacterium bradyrhizobium japonicum usda 110 contained gammacerane derivatives next to triterpenoids of the hopane series. diploptene, diplopterol, 2 beta-methyldiplopterol, aminobacteriohopanetriol and adenosylhopane were accompanied by tetrahymanol and the corresponding novel methylated homologues 2 beta-methyltetrahymanol, 20 alpha-methyltetrahymanol, and 2 beta,20 alpha-dimethyltetrahymanol. incorporation of [(2)h(3)]methyl-l-methionine indic ... | 2001 | 11231284 |
| crystal structure of the oxidized cytochrome c(2) from blastochloris viridis. | the crystal structure of the oxidized cytochrome c(2) from blastochloris (formerly rhodopseudomonas) viridis was determined at 1.9 a resolution. structural comparison with the reduced form revealed significant structural changes according to the oxidation state of the heme iron. slight perturbation of the polypeptide chain backbone was observed, and the secondary structure and the hydrogen patterns between main-chain atoms were retained. the oxidation state-dependent conformational shifts were l ... | 2001 | 11240122 |
| prediction of the transmembrane regions of beta-barrel membrane proteins with a neural network-based predictor. | a method based on neural networks is trained and tested on a nonredundant set of beta-barrel membrane proteins known at atomic resolution with a jackknife procedure. the method predicts the topography of transmembrane beta strands with residue accuracy as high as 78% when evolutionary information is used as input to the network. of the transmembrane beta-strands included in the training set, 93% are correctly assigned. the predictor includes an algorithm of model optimization, based on dynamic p ... | 2001 | 11274469 |
| metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "syntrophus aciditrophicus" strain sb in syntrophic association with h(2)-using microorganisms. | the metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "syntrophus aciditrophicus" in cocultures with hydrogen-using microorganisms was studied. cyclohexane carboxylate, cyclohex-1-ene carboxylate, pimelate, and glutarate (or their coenzyme a [coa] derivatives) transiently accumulated during growth with benzoate. identification was based on comparison of retention times and mass spectra of trimethylsilyl derivatives to the retention times and mass spectra of authe ... | 2001 | 11282627 |
| different mechanisms of the binding of soluble electron donors to the photosynthetic reaction center of rubrivivax gelatinosus and blastochloris viridis. | the tetraheme cytochrome subunits of the photosynthetic reaction centers (rcs) in two species of purple bacteria, rubrivivax gelatinosus and blastochloris (rhodopseudomonas) viridis, were compared in terms of their capabilities to bind different electron-donor proteins. the wild-type rcs from both species and mutated forms of r. gelatinosus rcs (with amino acid substitutions introduced to the binding domain for electron-donor proteins) were tested for their reactivity with soluble cytochromes an ... | 2001 | 11313347 |
| endotoxic properties of lipid a from comamonas testosteroni. | the lipid a from comamonas testosteroni has been isolated and its complete chemical structure determined [iida, t., haishima, y., tanaka, a., nishijima, k., saito, s. & tanamoto, k. (1996). eur j biochem 237, 468-475]. in this work, the relationship between its chemical structure and biological activity was studied. the lipid a was highly homogeneous chemically and was characterized by the relatively short chain length (c(10)) of the 3-hydroxy fatty acid components directly bound to the glucosam ... | 2001 | 11320112 |
| structure of the h subunit of the photosynthetic reaction center from the thermophilic purple sulfur bacterium, thermochromatium tepidum implications for the specific binding of the lipid molecule to the membrane protein complex. | the photosynthetic reaction center (rc) is a transmembrane protein complex that catalyzes light-driven electron transport across the photosynthetic membrane. the complete amino-acid sequence of the h subunit of the rc from a thermophilic purple sulfur bacterium, thermochromatium tepidum, has been determined for the first time among purple sulfur bacteria. the h subunit consists of 259 amino acids and has a molecular mass of 28 187. the deduced amino-acid sequences of this h subunit showed a sign ... | 2001 | 11322886 |
| proton uptake associated with the reduction of the primary quinone q(a) influences the binding site of the secondary quinone q(b) in rhodopseudomonas viridis photosynthetic reaction centers. | previously, two binding sites for the secondary quinone q(b) in the photosynthetic reaction center (rc) from rhodopseudomonas viridis were identified by x-ray crystallography, a 'proximal' binding site close to the non-heme iron, and a 'distal' site, displaced by 4.2 a along the path of the isoprenoid tail [c.r.d. lancaster and h. michel, structure 5 (1997) 1339-1359]. the quinone ring planes in the two sites differ by roughly a 180 degrees rotation around the isoprenoid tail. here we present mo ... | 2001 | 11334792 |
| intermolecular hydrogen bonding between carotenoid and bacteriochlorophyll in lh2. | we have studied van der waals contacts of the carotenoid rhodopin glucoside (rg) with the bacteriochlorophyll pigments absorbing at 800 nm (b800) in the crystal structure of rhodopseudomonas acidophila, and the hydrogen positions were determined from quantum chemical calculations at the hartree--fock (6-31g) level. we have found strong evidence for hydrogen bonding between the b800 bchl and the rg from neighboring protomer units. the binding energy was estimated to be about 2 kcal/mol (700 cm(-1 ... | 2001 | 11343702 |
| cu2+ site in photosynthetic bacterial reaction centers from rhodobacter sphaeroides, rhodobacter capsulatus, and rhodopseudomonas viridis. | the interaction of metal ions with isolated photosynthetic reaction centers (rcs) from the purple bacteria rhodobacter sphaeroides, rhodobacter capsulatus, and rhodopseudomonas viridis has been investigated with transient optical and magnetic resonance techniques. in rcs from all species, the electrochromic response of the bacteriopheophytin cofactors associated with q(a)(-)q(b) --> q(a)q(b)(-) electron transfer is slowed in the presence of cu(2+). this slowing is similar to the metal ion effect ... | 2001 | 11352751 |
| the gene transfer agent of rhodobacter capsulatus and "constitutive transduction" in prokaryotes. | transduction, bacteriophage-mediated gene transfer, is thought to play an important role in the evolution of prokaryote genomes. several gene transfer agents that resemble transducing phages have been found in diverse prokaryotes. this mini-review discusses these interesting agents of genetic exchange with a focus on the gene transfer agent (gta) of rhodobacter capsulatus, at present the only member of this group for which genetic information exists about the production of transducing particles. ... | 2001 | 11382219 |
| two-dimensional structure of the native light-harvesting complex lh2 from rubrivivax gelatinosus and of a truncated form. | the light-harvesting complex lh2 of rubrivivax gelatinosus has an oligomeric structure built from alpha-beta heterodimers containing three bacteriochlorophylls and one carotenoid each. the alpha subunit (71 residues) presents a c-terminal hydrophobic extension (residues 51-71) which is prone to attack by an endogenous protease. this extension can also be cleaved by a mild thermolysin treatment, as demonstrated by electrophoresis and by matrix-assisted laser desorption-time of flight mass spectro ... | 2001 | 11418098 |
| biomass production and studies on rhodopseudomonas palustris grown in an outdoor, temperature controlled, underwater tubular photobioreactor. | a temperature controlled underwater tubular photobioreactor was studied for 6 months in outdoor conditions to determine biomass production of rhodopseudomonas palustris 42ol. biomass output rate was very high during the study period. in july, productivity was about 75.0 g reactor(-1) d(-1) for a short period (5 days). the biomass yield averaged 0.7 g biomass dry weight (d.w.)xg acetic acid(-1). we also obtained a mean photosynthetic efficiency of 7.6% in winter and 7.1% in summer. biomasses rich ... | 2001 | 11434969 |
| cytochrome c' folding triggered by electron transfer: fast and slow formation of four-helix bundles. | reduced (fe(ii)) rhodopseudomonas palustris cytochrome c' (cyt c') is more stable toward unfolding ([guhcl](1/2) = 2.9(1) m) than the oxidized (fe(iii)) protein ([guhcl](1/2) = 1.9(1) m). the difference in folding free energies (delta delta g(f) degrees = 70 mev) is less than half of the difference in reduction potentials of the folded protein (100 mv vs. nhe) and a free heme in aqueous solution ( approximately -150 mv). the spectroscopic features of unfolded fe(ii)-cyt c' indicate a low-spin he ... | 2001 | 11438728 |
| ultrahigh field mas nmr dipolar correlation spectroscopy of the histidine residues in light-harvesting complex ii from photosynthetic bacteria reveals partial internal charge transfer in the b850/his complex. | low-temperature 15n and 13c cp/mas (cross-polarization/magic angle spinning) nmr has been used to analyze bchl-histidine interactions and the electronic structure of histidine residues in the light-harvesting complex ii (lh2) of rhodopseudomonas acidophila. the histidines were selectively labeled at both or one of the two nitrogen sites of the imidazole ring. the resonances of histidine nitrogens that are interacting with b850 bchl a have been assigned. specific 15n labeling confirmed that it is ... | 2001 | 11457290 |
| single-cell gel/comet assay applied to the analysis of uv radiation-induced dna damage in rhodomonas sp. (cryptophyta). | the single-cell gel/comet assay is an electrophoretic technique used to detect single-strand breaks in dna. damage is assessed examining individual cells under an epifluorescent microscope. uv-induced dna damage consists mostly of the formation of pyrimidine dimers; therefore, most of the damage cannot be detected using a standard comet assay. the enzyme t4 endonuclease v breaks dna strands at sites of pyrimidine dimers. the main objective of this work is to evaluate the comet assay to detect uv ... | 2001 | 11460537 |
| the crystallographic structure of the b800-820 lh3 light-harvesting complex from the purple bacteria rhodopseudomonas acidophila strain 7050. | the b800-820, or lh3, complex is a spectroscopic variant of the b800-850 lh2 peripheral light-harvesting complex. lh3 is synthesized by some species and strains of purple bacteria when growing under what are generally classed as "stressed" conditions, such as low intensity illumination and/or low temperature (<30 degrees c). the apoproteins in these complexes modify the absorption properties of the chromophores to ensure that the photosynthetic process is highly efficient. the crystal structure ... | 2001 | 11467938 |
| measuring the immeasurable. | | 2001 | 11484018 |
| growth of the purple bacterium rhodobacter capsulatus on the aromatic compound hippurate. | the purple nonsulfur bacterium rhodobacter capsulatus strain b10 grew phototrophically on the aromatic compound hippurate (n-benzoyl-l-glycine) and related benzoyl amino acids. absorption spectra, extraction, and gc/ms analysis of culture supernatants showed that hippurate was stoichiometrically converted to benzoate and glycine, with the latter used as a carbon or nitrogen source for growth. this conclusion was supported by detection of the enzyme hippuricase in permeabilized intact cells. chem ... | 2001 | 11491088 |
| aeration conditions affecting growth of purple nonsulfur bacteria in an organic wastewater treatment process. | effects of aeration on purple nonsulfur bacteria (pnsb) were studied in photobioreactors. bacterial community changes were analyzed by denaturing gradient gel electrophoresis (dgge) and fluorescence in situ hybridization (fish). dgge band pattern change was small and only few prominent bands were obtained at non-aeration condition. sequencing results of the prominent dgge bands obtained at this condition revealed that they represented mainly the pnsb, rhodobacter sphaeroides and rhodopseudomonas ... | 2001 | 11518335 |
| structure, expression and products of the ribosomal rna operons of rhodopseudomonas palustris no. 7. | rhodopseudomonas palustris strains carry one or two ribosomal rrna operons, and those with duplicated rrn operons grow faster. the two rrn operons in r. palustris no. 7 are virtually identical over a 54,70-bp stretch containing the genes for 16s rrna, trnaile, trnaala, 23s rrna and 5s rrna, as well as the intergenic spacers and part of the extragenic spacer. in r. palustris, unlike most bacteria with multiple rrn operons, the putative promoter sequences of the two operons are highly diverged, su ... | 2001 | 11523795 |
| identification and characterization of rhodopseudomonas spp., a purple, non-sulfur bacterium from microbial mats. | a species of facultative photo-organotrophic, purple, non-sulfur bacterium was isolated from mixed-species microbial mats, characterized and examined for metal tolerance and bioremediation potential. contributing mats were natural consortia of microbes, dominated by cyanobacteria and containing several species of bacteria arranged in a laminar structure, stabilized within a gel matrix. constructed microbial mats were used for bioremediation of heavy metals and organic chemical pollutants. purple ... | 2001 | 11535416 |
| lifetimes of bacteriochlorophyll fluorescence in rhodopseudomonas viridis and heliobacterium chlorum at low temperatures. | fluorescence lifetimes of isolated membranes of rhodopseudomonas viridis were measured in the temperature range of 77 k to 25 k. at room temperature, the main component of the fluorescence decay of bacteriochlorophyll (bchl) b had a time constant of 50 ps. in contrast to other purple bacteria, the emission at low temperature was spectrally homogeneous and showed essentially single lifetimes of 140 ps at 77 k and 180 ps at 25 k, with the primary electron donor in the oxidized state. taking int ... | 1993 | 11537866 |
| a novel directly coupled gradostat. | the original bidirectional compound chemostat (gradostat) described by lovitt and wimpenny has been simplified by making a more compact apparatus in which chemical gradients are established by diffusion between adjacent culture chambers. the experimental model (diffusion coupled (dc) gradostat) consisted of five chambers whose contents could be agitated by turbines rotating in the horizontal plane on a common shaft. two biological experiments were designed to reveal the value of the dc gradost ... | 1992 | 11540058 |
| the phylogeny of purple bacteria: the alpha subdivision. | the technique of oligonucleotide cataloging shows the purple photosynthetic eubacteria to comprise three major subdivisions, temporarily called alpha, beta, and gamma--previously designated groups i-iii by gibson et al. (1979). each subdivision contains a number of non-photosynthetic genera in addition to the photosynthetic ones. the alpha subdivision, the subject of the present report, contains most but not all of the species that fall into the classically defined genera rhodospirillum, rhodo ... | 1984 | 11541974 |
| recombination reduction of photooxidized cytochrome c in reaction centers of rhodopseudomonas viridis at low temperature. | the temperature dependence of dark reduction of photooxidized cytochrome c was studied in isolated preparations of rhodopseudomonas viridis reaction centers. within the range from room temperature to approximately 260 k this process was found to be mediated by thermal diffusion of exogenous donor molecules, whereas at lower temperatures photooxidized cytochrome is reduced as a result of indirect recombination with photoreduced primary quinone acceptor. kinetic simulation allowed certain thermody ... | 2001 | 11563957 |
| transfer of rhodopseudomonas acidophila to the new genus rhodoblastus as rhodoblastus acidophilus gen. nov., comb. nov. | rhodopseudomonas acidophila has unique properties among the phototrophic alpha-proteobacteria and is quite distinct from the type species of rhodopseudomonas, rhodopseudomonas palustris. therefore, the transfer of rhodopseudomonas acidophila to rhodoblastus acidophilus gen. nov., comb. nov., is proposed. this proposal is in accordance with other taxonomic reclassifications proposed previously and fully reflects the phylogenetic distance from rhodopseudomonas palustris. | 2001 | 11594619 |
| 1h nmr study of the reduced cytochrome c' from rhodopseudomonas palustris containing a high-spin iron(ii) heme moiety. | the assignment of the hyperfine shifted signals of the reduced cytochrome c' from rhodopseudomonas palustris has been obtained through saturation transfer experiments with assigned signals of the high-spin oxidized protein and through tailored experiments to reveal proton-proton dipolar connectivities in paramagnetic molecules. the peculiar shift pattern consisting of the 1-, 8-, and 5-methyl signals shifted upfield and the 3-methyl signal downfield, which is shared by all cytochromes c' so far ... | 1998 | 11670644 |
| hydrophobicity and prediction of the secondary structure of membrane proteins and peptides. | reliability of the hydropathy method to predict the formation of membrane-spanning alpha-helices by integral membrane proteins and peptides whose structure is known from x-ray crystallography is analysed. it is shown that kyte-doolittle hydropathy plots do not predict accurately 22 transmembrane alpha-helices in the reaction centres (rc) of the photosynthetic bacteria rhodopseudomonas viridis and rhodobacter sphaeroides (r-26). the accuracy of prediction for these proteins was improved using an ... | 2001 | 11699870 |
| microbial genomes. sequences reveal borrowed genes. | | 2001 | 11721026 |
| dynamics of excitation energy transfer in the lh1 and lh2 light-harvesting complexes of photosynthetic bacteria. | photosynthetic light harvesting is a unique life process that occurs with amazing efficiency. since the discovery of the structure of the bacterial peripheral light-harvesting complex (lh2), this process has been studied using a variety of advanced laser spectroscopic methods. we are now in a position to discuss the physical origins of excitation energy transfer and trapping in the lh2 and lh1 antennae of photosynthetic purple bacteria. we demonstrate that the time evolution of the state created ... | 2001 | 11735388 |
| cleavage of the iron-methionine bond in c-type cytochromes: crystal structure of oxidized and reduced cytochrome c(2) from rhodopseudomonas palustris and its ammonia complex. | the three-dimensional structures of the native cytochrome c(2) from rhodopseudomonas palustris and of its ammonia complex have been obtained at ph 4.4 and ph 8.5, respectively. the structure of the native form has been refined in the oxidized state at 1.70 a and in the reduced state at 1.95 a resolution. these are the first high-resolution crystal structures in both oxidation states of a cytochrome c(2) with relatively high redox potential (+350 mv). the differences between the two oxidation sta ... | 2002 | 11742117 |
| [biological effects of space flight on purple nonsulfur photosynthetic bacteria]. | to study biological effects of space flight on purple nonsulfur photosynthetic bacteria. | 1999 | 11765775 |
| simultaneous determination of delta-aminolevulinic acid, porphobilinogen, levulinic acid and glycine in culture broth by capillary electrophoresis. | capillary electrophoretic simultaneous determination of a mixture containing delta-aminolevulinic acid, porphobilinogen, levulinic acid and glycine was investigated. with increases in the sodium tetraborate buffer concentration (5-70 mm), resolution of the four components was improved, but the migration time was increased. alternatively, with increases in the applied voltage (5-22.5 kv), a shortened migration time was seen but this adversely affected resolution. the components were separated wit ... | 2001 | 11771832 |
| the 7.5-a electron density and spectroscopic properties of a novel low-light b800 lh2 from rhodopseudomonas palustris. | a novel low-light (ll) adapted light-harvesting complex ii has been isolated from rhodopseudomonas palustris. previous work has identified a ll b800-850 complex with a heterogeneous peptide composition and reduced absorption at 850 nm. the work presented here shows the 850 nm absorption to be contamination from a high-light b800-850 complex and that the true ll light-harvesting complex ii is a novel b800 complex composed of eight alpha beta(d) peptide pairs that exhibits unique absorption and ci ... | 2002 | 11806936 |
| the aquatic budding bacterium blastobacter denitrificans is a nitrogen-fixing symbiont of aeschynomene indica. | blastobacter spp. are freshwater bacteria that form rosette structures by cellular attachment to a common base. comparative analyses of ribosomal 16s rrna gene and internally transcribed spacer region sequences indicated that b. denitrificans is a member of the alpha-subdivision of proteobacteria. among the alpha-proteobacteria, b. denitrificans was related to a cluster of genera, including rhodopseudomonas palustris, afipia felis, nitrobacter hamburgensis, and bradyrhizobium spp. although the p ... | 2002 | 11872460 |
| enzymatic synthesis and purification of aromatic coenzyme a esters. | two recombinant his-tagged proteins, a plant 4-coumarate:coenzyme a ligase (ec 6.2.1.12) and a bacterial benzoate:coenzyme a ligase (ec 6.2.1.25), were expressed in escherichia coli and purified in a single step using ni-chelating chromatography. purified enzymes were used to synthesize cinnamoyl-coenzyme a (coa), p-coumaroyl-coa, feruloyl-coa, caffeoyl-coa, and benzoyl-coa. conversions up to 95% were achieved. using a rapid solid-phase extraction procedure, the target coa esters were isolated w ... | 2002 | 11878812 |
| absorption and cd spectroscopy and modeling of various lh2 complexes from purple bacteria. | the absorption (od) and circular dichroism (cd) spectra of lh2 complexes from various purple bacteria have been measured and modeled. based on the lineshapes of the spectra we can sort the lh2 complexes into two distinguishable groups: "acidophila"-like (type 1) and "molischianum"-like (type 2). starting from the known geometric structures of rhodopseudomonas (rps.) acidophila and rhodospirillum (rsp.) molischianum we can model the od and cd spectra of all species by just slightly varying some k ... | 2002 | 11916874 |
| isolation of 5,6-dimethylbenzimidazolyl cobamide coenzyme from rhodopseudomonas spheroides. | | 1970 | 11945404 |
| sulphydryl groups and the in vitro enzymatic synthesis of 5-amino-laevulinic acid and porphobilinogen in rhodopseudomonas spheroides. | | 1971 | 11946041 |
| energy transduction in photosynthetic bacteria iii. coincidence of coupling factor of photosynthesis and respiration in rhodopseudomonas capsulata. | | 1972 | 11946493 |
| the lack of carotenoid band shifts in a non-photosynthetic, reaction centerless mutant of rhodopseudomonas spheroides. | | 1972 | 11946579 |
| some observations on the primary acceptor of rhodopseudomonas viridis. | | 1972 | 11946833 |
| acetate utilisation by rhodopseudomonas spheroides. | | 1969 | 11947144 |
| the high energy state in chromatophores from rhodopseudomonas spheroides. | | 1969 | 11947178 |
| activation by hg(2+) of acetoacetyl-coa reductase in extracts of rhodopseudomonas spheroides and rhodomicrobium vannielii. | | 1969 | 11947289 |
| relationship between hydrogen-bonding network and reduction potential in c-type cytochromes. | | 2002 | 11959147 |
| taxis response of various denitrifying bacteria to nitrate and nitrite. | the taxis response of rhodobacter sphaeroides 2.4.1 and 2.4.3, rhodopseudomonas palustris, and agrobacterium tumefaciens to nitrate and nitrite was evaluated by observing the macroscopic behavior of cells suspended in soft agar and incubated under various conditions. r. sphaeroides 2.4.3, which is capable of both nitrate and nitrite reduction, showed a taxis response to both nitrate and nitrite. r. sphaeroides 2.4.1, which contains nitrate reductase but not nitrite reductase, did not show a taxi ... | 2002 | 11976082 |
| photosynthetic apparatus of purple bacteria. | | 2002 | 11997980 |
| bacteriophytochrome controls photosystem synthesis in anoxygenic bacteria. | plants use a set of light sensors to control their growth and development in response to changes in ambient light. in particular, phytochromes exert their regulatory activity by switching between a biologically inactive red-light-absorbing form (pr) and an active far-red-light absorbing form (pfr). recently, biochemical and genetic studies have demonstrated the occurrence of phytochrome-like proteins in photosynthetic and non-photosynthetic bacteria--but little is known about their functions. he ... | 2002 | 12000965 |
| effect of protein relaxation on electron transfer from the cytochrome subunit to the bacteriochlorophyll dimer in rps. sulfoviridis reaction centers within mixed adiabatic/nonadiabatic model. | the broad set of nonexponential electron transfer (et) kinetics in reaction centers (rc) from rhodopseudomonas sulfoviridis in temperature range 297-40 k are described within a mixed adiabatic/nonadiabatic model. the key point of the model is the combination of sumi-marcus and rips-jortner approaches which can be represented by the separate contributions of temperature-independent vibrational (v) and temperature-dependent diffusive (d) coordinates to the preexponential factor, to the free energy ... | 2002 | 12009432 |
| bioreactor design studies for a hydrogen-producing bacterium. | carbon monoxide (co) can be metabolized by a number of microorganisms along with water to produce hydrogen (h2) and carbon dioxide. national renewable energy laboratory researchers have isolated a number of bacteria that perform this so-called water-gas shift reaction at ambient temperatures. we performed experiments to measure the rate of co conversion and h2 production in a trickle-bed reactor (tbr). the liquid recirculation rate and the reactor support material both affected the mass transfer ... | 2002 | 12018287 |
| phototrophic transformation of phenol to 4-hydroxyphenylacetate by rhodopseudomonas palustris. | newly isolated and culture collection strains of rhodopseudomonas palustris were able to transform phenol to 4-hydroxyphenylacetate under phototrophic conditions in the presence of acetate, malate, benzoate, or cinnamate as growth substrates. the reaction was examined with uniformly (14)c-labelled phenol and the product was identified by hplc retention time, uv-scans, and (1)h- and (13)c-nmr analysis. the transformation reaction was detectable in cell-free extracts in the presence of nad(+) and ... | 2002 | 12021805 |
| kinetics, energetics, and electronic coupling of the primary electron transfer reactions in mutated reaction centers of blastochloris viridis. | femtosecond spectroscopy in combination with site-directed mutagenesis has been used to study the dynamics of primary electron transfer in native and 12 mutated reaction centers of blastochloris (b) (formerly called rhodopseudomonas) viridis. the decay times of the first excited state p* vary at room temperature between of 0.6 and 50 ps, and at low temperatures between 0.25 and 90 ps. these changes in time constants are discussed within the scope of nonadiabatic electron transfer theory using di ... | 2002 | 12023243 |
| quantum control of energy flow in light harvesting. | coherent light sources have been widely used in control schemes that exploit quantum interference effects to direct the outcome of photochemical processes. the adaptive shaping of laser pulses is a particularly powerful tool in this context: experimental output as feedback in an iterative learning loop refines the applied laser field to render it best suited to constraints set by the experimenter. this approach has been experimentally implemented to control a variety of processes, but the extent ... | 2002 | 12037563 |
| evolutionary relationship of phototrophic bacteria in the alpha-proteobacteria based on farnesyl diphosphate synthase. | partial sequences of farnesyl diphosphate (fpp) synthase genes derived from the rhodobacter-rhodovulum group and from the rhodopseudomonas palustris-bradyrhizobium japonicum group of the alpha-proteobacteria were subjected to phylogenetic analysis to investigate the relationships of phototrophic and non-phototrophic bacteria in the alpha-proteobacteria . the four rhodovulum species formed a monophyletic group within the rhodobacter cluster, and agrobacterium ferrugineum iam 12616(t) intermingled ... | 2002 | 12055311 |
| genotypic and phenotypic diversity within species of purple nonsulfur bacteria isolated from aquatic sediments. | to assess the extent of genotypic and phenotypic diversity within species of purple nonsulfur bacteria found in aquatic sediments, a total of 128 strains were directly isolated from agar plates that had been inoculated with sediment samples from haren and de biesbosch in the netherlands. all isolates were initially characterized by box-pcr genomic dna fingerprinting, and 60 distinct genotypes were identified. analyses of 16s rrna gene sequences of representatives of each genotype showed that fiv ... | 2002 | 12089030 |
| heterologous expression of a bacterial homospermidine synthase gene in transgenic tobacco: effects on the polyamine pathway. | homospermidine synthase (hss) is a branch-point enzyme that links the secondary pathway (pyrrolizidine alkaloids) to primary metabolism (polyamines). since the diamine putrescine is a precursor of homospermidine and nicotine in tobacco, we performed heterologous expression of a bacterial homospermidine synthase gene (hss)in nicotiana tabacum and determined the effect on free and conjugated polyamine levels. the hss gene from rhodopseudomonas viridis was placed under the control of the cauliflowe ... | 2002 | 12112034 |
| cysteine activation is an inherent in vitro property of prolyl-trna synthetases. | aminoacyl-trna synthetases are well known for their remarkable precision in substrate selection during aminoacyl-trna formation. some synthetases enhance the accuracy of this process by editing mechanisms that lead to hydrolysis of incorrectly activated and/or charged amino acids. prolyl-trna synthetases (prorss) can be divided into two structurally divergent groups, archaeal-type and bacterial-type enzymes. a striking difference between these groups is the presence of an insertion domain (appro ... | 2002 | 12130657 |
| conservation of the free energy change of the alkaline isomerization in mitochondrial and bacterial cytochromes c. | the thermodynamic parameters of the alkaline transition for oxidized native yeast iso-1 cytochrome c and rhodopseudomonas palustris cytochrome c(2) (cytc(2)) have been determined through direct electrochemistry experiments carried out at variable ph and temperature and compared to those for horse and beef heart cytochromes c. we have found that both transition enthalpy and entropy are remarkably species dependent, following the order r. palustris cytc(2) >> beef (horse) heart cytc>yeast iso-1 cy ... | 2002 | 12147260 |
| aerobic metabolism of phenylacetic acids in azoarcus evansii. | the aerobic metabolism of phenylacetic acid (pa) and 4-hydroxyphenylacetic acid (4-ohpa) was investigated in the beta-proteobacterium azoarcus evansii. evidence for the existence of two independent catabolic pathways for pa and 4-ohpa is presented. 4-ohpa metabolism involves the formation of 2,5-dihydroxyphenylacetate (homogentisate) and maleylacetoacetate catalyzed by specifically induced 4-ohpa 1-monooxygenase and homogentisate 1,2-dioxygenase. the metabolism of pa starts by its activation to ... | 2002 | 12189419 |
| spectroscopy on individual light-harvesting 1 complexes of rhodopseudomonas acidophila. | in this paper the fluorescence-excitation spectra of individual lh1-rc complexes (rhodopseudomonas acidophila) at 1.2 k are presented. all spectra show a limited number of broad bands with a characteristic polarization behavior, indicating that the excitations are delocalized over a large number of pigments. a significant variation in the number of bands, their bandwidths, and polarization behavior is observed. only 30% of the spectra carry a clear signature of delocalized excited states of a ci ... | 2002 | 12202393 |
| in search of a bacterial species definition. 1997. | | 2002 | 12362904 |
| [hydrogen photoproduction from acetate by rhodopseudomonas palustris]. | based on the characteristics of metabolism of photosynthetic bacteria and the major kinds of organic compounds produced in wastewater degradation, eleven kinds of organic compounds were chosen for hydrogen photoproduction using rhodopseudomonas palustris z strain. the maximal volumetric h2 productivity was obtained using acetate as the sole carbon source and electron donor. the kinetics of cell growth and h2 liberation, and the influences of several major limiting factors on photoevolution of h2 ... | 2002 | 12385249 |
| vibrational spectroscopy favors a unique qb binding site at the proximal position in wild-type reaction centers and in the pro-l209 --> tyr mutant from rhodobacter sphaeroides. | in the various x-ray structures of native reaction centers (rcs) from the photosynthetic bacterium rhodobacter sphaeroides, two distinct main binding sites (distal and proximal) for the secondary quinone q(b) have been described in the literature. the movement of q(b) from its distal to proximal position has been proposed to account for the conformational gate limiting the rate of the first electron transfer from the primary quinone q(a-) to q(b). recently, q(b) was found to bind in the proximal ... | 2002 | 12390017 |
| evolutionary implications of phylogenetic analyses of the gene transfer agent (gta) of rhodobacter capsulatus. | the gene transfer agent (gta) of the a-proteobacterium rhodobacter capsulatus is a cell-controlled genetic exchange vector. genes that encode the gta structure are clustered in a 15-kb region of the r. capsulatus chromosome, and some of these genes show sequence similarity to known bacteriophage head and tail genes. however, the production of gta is controlled at the level of transcription by a cellular two-component signal transduction system. this paper describes homologues of both the gta str ... | 2002 | 12399927 |
| characterization of the rrna locus of pfiesteria piscicida and development of standard and quantitative pcr-based detection assays targeted to the nontranscribed spacer. | pfiesteria piscicida is a heterotrophic dinoflagellate widely distributed along the middle atlantic shore of the united states and associated with fish kills in the neuse river (north carolina) and the chesapeake bay (maryland and virginia). we constructed a genomic dna library from clonally cultured p. piscicida and characterized the nontranscribed spacer (nts), small subunit, internal transcribed spacer 1 (its1), 5.8s region, its2, and large subunit of the rrna gene cluster. based on the p. pi ... | 2002 | 12406730 |
| protein-lipid interactions in the purple bacterial reaction centre. | the purple bacterial reaction centre uses the energy of sunlight to power energy-requiring reactions such as the synthesis of atp. during the last 20 years, a combination of x-ray crystallography, spectroscopy and mutagenesis has provided a detailed insight into the mechanism of light energy transduction in the bacterial reaction centre. in recent years, structural techniques including x-ray crystallography and neutron scattering have also been used to examine the environment of the reaction cen ... | 2002 | 12409196 |
| rhodopseudomonas acidophila strain 10050 contains photosynthetic lh2 antenna complexes that are not enriched with phosphatidylglycerol, and the phospholipids have a fatty acyl composition that is unusual for purple non-sulfur bacteria. | the phospholipid composition of rhodopseudomonas acidophila strain 10050 grown aerobically or anaerobically in the light was determined. the major phospholipids present in the aerobic cells were phosphatidylethanolamine (pe; 54%), phosphatidylglycerol (pg; 24%) and cardiolipin (diphosphatidylglycerol, dpg) (14%), together with phosphatidylcholine (pc; 5%). on moving the cells to anaerobic photosynthetic growth in the light pe remained the major phospholipid (37-49%), but there was a major change ... | 2002 | 12460683 |
| time-resolved dissociation of the light-harvesting 1 complex of rhodospirillum rubrum, studied by infrared laser temperature jump. | for the first time, data are presented on the time-resolved disassembly reaction of a highly organized membrane protein complex in vitro. the photosynthetic core light-harvesting complex of the bacterial strain rhodospirillum rubrum g9 consists of 12-16 dimeric subunits that in vivo are associated with the photosynthetic reaction center in a ringlike manner. isolated in a detergent solution, its appearance either as a ringlike complex (called b873 and absorbing at 873 nm), subunit dimer (called ... | 2002 | 12484747 |
| on the involvement of the water-polaron mechanism in energy trapping by reaction centers of purple bacteria. | a locus for binding a mobile water molecule was searched for in the immediate vicinity of the special pair in the reaction center. using the proteus pc-program (a part of the grasp package) atomic structures of the reaction centers were analyzed in purple bacteria rhodopseudomonas viridis and rhodobacter sphaeroides. in both structures the loci for binding mobile water molecules were found at the distance of about 4.5 a from the middle of the special pair in the reaction center. the reorientatio ... | 2002 | 12495417 |
| cloning, heterologous expression, and characterization of recombinant class ii cytochromes c from rhodopseudomonas palustris. | the cytochrome (cyt) c', cyt c(556), and cyt c(2) genes from rhodopseudomonas palustris have been cloned; recombinant cyt c' and cyt c(556) have been expressed, purified, and characterized. unlike mitochondrial cyt c, these two proteins are structurally similar to cyt b(562), in which the heme is embedded in a four-helix bundle. the hemes in both recombinant proteins form covalent thioether links to two cys residues. uv/vis spectra of the fe(ii) and fe(iii) states of the recombinant cyts are ide ... | 2003 | 12495812 |