Publications

cbr antimicrobials inhibit rna polymerase via at least two bridge-helix cap-mediated effects on nucleotide addition.	rna polymerase inhibitors like the cbr class that target the enzyme's complex catalytic center are attractive leads for new antimicrobials. catalysis by rna polymerase involves multiple rearrangements of bridge helix, trigger loop, and active-center side chains that isomerize the triphosphate of bound ntp and two mg(2+) ions from a preinsertion state to a reactive configuration. cbr inhibitors target a crevice between the n-terminal portion of the bridge helix and a surrounding cap region within ...	2015	26195788
trna recognition by a bacterial trna xm32 modification enzyme from the spout methyltransferase superfamily.	trmj proteins from the spout methyltransferase superfamily are trna xm32 modification enzymes that occur in bacteria and archaea. unlike archaeal trmj, bacterial trmj require full-length trna molecules as substrates. it remains unknown how bacterial trmjs recognize substrate trnas and specifically catalyze a 2'-o modification at ribose 32. herein, we demonstrate that all six escherichia coli (ec) trnas with 2'-o-methylated nucleosides at position 32 are substrates of ectrmj, and we show that the ...	2015	26202969
complete genome sequence and description of salinispira pacifica gen. nov., sp. nov., a novel spirochaete isolated form a hypersaline microbial mat.	during a study of the anaerobic microbial community of a lithifying hypersaline microbial mat of lake 21 on the kiritimati atoll (kiribati republic, central pacific) strain l21-rpul-d2(t) was isolated. the closest phylogenetic neighbor was spirochaeta africana z-7692(t) that shared a 16s rrna gene sequence identity value of 90% with the novel strain and thus was only distantly related. a comprehensive polyphasic study including determination of the complete genome sequence was initiated to chara ...	2015	26203324
profile of dinshaw j. patel.		2015	26216951
structures and functions of the multiple kow domains of transcription elongation factor spt5.	the eukaryotic spt4-spt5 heterodimer forms a higher-order complex with rna polymerase ii (and i) to regulate transcription elongation. extensive genetic and functional data have revealed diverse roles of spt4-spt5 in coupling elongation with chromatin modification and rna-processing pathways. a mechanistic understanding of the diverse functions of spt4-spt5 is hampered by challenges in resolving the distribution of functions among its structural domains, including the five kow domains in spt5, a ...	2015	26217010
biochemical and structural properties of a thermostable mercuric ion reductase from metallosphaera sedula.	mercuric ion reductase (mera), a mercury detoxification enzyme, has been tuned by evolution to have high specificity for mercuric ions (hg(2+)) and to catalyze their reduction to a more volatile, less toxic elemental form. here, we present a biochemical and structural characterization of mera from the thermophilic crenarchaeon metallosphaera sedula. mera from m. sedula is a thermostable enzyme, and remains active after extended incubation at 97°c. at 37°c, the nadph oxidation-linked hg(2+) reduc ...	2015	26217660
ratcheting of rna polymerase toward structural principles of rna polymerase operations.	rna polymerase (rnap) performs various tasks during transcription by changing its conformational states, which are gradually becoming clarified. a recent study focusing on the conformational transition of rnap between the ratcheted and tight forms illuminated the structural principles underlying its functional operations.	2015	26226152
x-ray structure determination using low-resolution electron microscopy maps for molecular replacement.	structures of multisubunit macromolecular machines are primarily determined either by electron microscopy (em) or by x-ray crystallography. in many cases, a structure for a complex can be obtained at low resolution (at a coarse level of detail) with em and at a higher resolution (with finer detail) by x-ray crystallography. the integration of these two structural techniques is becoming increasingly important for the generation of atomic models of macromolecular complexes. a low-resolution em ima ...	2015	26226459
implication from the predicted docked interaction of sigma h and exploration of its interaction with rna polymerase in mycobacterium tuberculosis.	m. tuberculosis is adapted to remain active in the extreme environmental condition due to the presence of atypical sigma factors commonly called extra cytoplasmic function (ecf) sigma factors. among the 13 sigma factors of m. tuberculosis, 10 are regarded as the ecf sigma factor that exerts their attributes in various stress response. therefore it is of interest to describe the structural prediction of one of the ecf sigma factors, sigma h (sigh), involved in oxidative and heat stress having int ...	2015	26229290
activation of gtp hydrolysis in mrna-trna translocation by elongation factor g.	during protein synthesis, elongation of the polypeptide chain by each amino acid is followed by a translocation step in which mrna and transfer rna (trna) are advanced by one codon. this crucial step is catalyzed by elongation factor g (ef-g), a guanosine triphosphatase (gtpase), and accompanied by a rotation between the two ribosomal subunits. a mutant of ef-g, h91a, renders the factor impaired in guanosine triphosphate (gtp) hydrolysis and thereby stabilizes it on the ribosome. we use cryogeni ...	2015	26229983
crucial hsp70 co-chaperone complex unlocks metazoan protein disaggregation.	protein aggregates are the hallmark of stressed and ageing cells, and characterize several pathophysiological states. healthy metazoan cells effectively eliminate intracellular protein aggregates, indicating that efficient disaggregation and/or degradation mechanisms exist. however, metazoans lack the key heat-shock protein disaggregase hsp100 of non-metazoan hsp70-dependent protein disaggregation systems, and the human hsp70 system alone, even with the crucial hsp110 nucleotide exchange factor, ...	2015	26245380
linkage of catalysis and 5' end recognition in ribonuclease rnase j.	in diverse bacterial species, the turnover and processing of many rnas is mediated by the ribonuclease rnase j, a member of the widely occurring metallo-β-lactamase enzyme family. we present crystal structures of streptomyces coelicolor rnase j with bound rna in pre- and post-cleavage states, at 2.27 å and 2.80 å resolution, respectively. these structures reveal snapshots of the enzyme cleaving substrate directionally and sequentially from the 5' terminus. in the pre-cleavage state, a water mole ...	2015	26253740
multiple conversion between the genes encoding bacterial class-i release factors.	bacteria require two class-i release factors, rf1 and rf2, that recognize stop codons and promote peptide release from the ribosome. rf1 and rf2 were most likely established through gene duplication followed by altering their stop codon specificities in the common ancestor of extant bacteria. this scenario expects that the two rf gene families have taken independent evolutionary trajectories after the ancestral gene duplication event. however, we here report two independent cases of conversion b ...	2015	26257102
initiation of mrna translation in bacteria: structural and dynamic aspects.	initiation of mrna translation is a major checkpoint for regulating level and fidelity of protein synthesis. being rate limiting in protein synthesis, translation initiation also represents the target of many post-transcriptional mechanisms regulating gene expression. the process begins with the formation of an unstable 30s pre-initiation complex (30s pre-ic) containing initiation factors (ifs) if1, if2 and if3, the translation initiation region of an mrna and initiator fmet-trna whose codon and ...	2015	26259514
molecular basis of ribosome recognition and mrna hydrolysis by the e. coli yafq toxin.	bacterial type ii toxin-antitoxin modules are protein-protein complexes whose functions are finely tuned by rapidly changing environmental conditions. e. coli toxin yafq is suppressed under steady state growth conditions by virtue of its interaction with its cognate antitoxin, dinj. during stress, dinj is proteolytically degraded and free yafq halts translation by degrading ribosome-bound mrna to slow growth until the stress has passed. although structures of the ribosome with toxins rele and yo ...	2015	26261214
the photochemical mechanism of a b12-dependent photoreceptor protein.	the coenzyme b12-dependent photoreceptor protein, carh, is a bacterial transcriptional regulator that controls the biosynthesis of carotenoids in response to light. on binding of coenzyme b12 the monomeric apoprotein forms tetramers in the dark, which bind operator dna thus blocking transcription. under illumination the carh tetramer dissociates, weakening its affinity for dna and allowing transcription. the mechanism by which this occurs is unknown. here we describe the photochemistry in carh t ...	2015	26264192
a conserved histidine in switch-ii of ef-g moderates release of inorganic phosphate.	elongation factor g (ef-g), a translational gtpase responsible for trna-mrna translocation possesses a conserved histidine (h91 in escherichia coli) at the apex of switch-ii, which has been implicated in gtpase activation and gtp hydrolysis. while h91a, h91r and h91e mutants showed different degrees of defect in ribosome associated gtp hydrolysis, h91q behaved like the wt. however, all these mutants, including h91q, are much more defective in inorganic phosphate (pi) release, thereby suggesting ...	2015	26264741
collaborative protein filaments.	it is now well established that prokaryotic cells assemble diverse proteins into dynamic cytoskeletal filaments that perform essential cellular functions. although most of the filaments assemble on their own to form higher order structures, growing evidence suggests that there are a number of prokaryotic proteins that polymerise only in the presence of a matrix such as dna, lipid membrane or even another filament. matrix-assisted filament systems are frequently nucleotide dependent and cytomotiv ...	2015	26271102
degenerate connective polypeptide 1 (cp1) domain from human mitochondrial leucyl-trna synthetase.	the connective polypeptide 1 (cp1) editing domain of leucyl-trna synthetase (leurs) from various species either harbors a conserved active site to exclude trna mis-charging with noncognate amino acids or is evolutionarily truncated or lost because there is no requirement for high translational fidelity. however, human mitochondrial leurs (hmtleurs) contains a full-length but degenerate cp1 domain that has mutations in some residues important for post-transfer editing. the significance of such an ...	2015	26272616
allosteric activation of bacterial swi2/snf2 (switch/sucrose non-fermentable) protein rapa by rna polymerase: biochemical and structural studies.	members of the swi2/snf2 (switch/sucrose non-fermentable) family depend on their atpase activity to mobilize nucleic acid-protein complexes for gene expression. in bacteria, rapa is an rna polymerase (rnap)-associated swi2/snf2 protein that mediates rnap recycling during transcription. it is known that the atpase activity of rapa is stimulated by its interaction with rnap. it is not known, however, how the rapa-rnap interaction activates the enzyme. previously, we determined the crystal structur ...	2015	26272746
recent advances in biosynthetic modeling of nitric oxide reductases and insights gained from nuclear resonance vibrational and other spectroscopic studies.	this forum article focuses on recent advances in structural and spectroscopic studies of biosynthetic models of nitric oxide reductases (nors). nors are complex metalloenzymes found in the denitrification pathway of earth's nitrogen cycle where they catalyze the proton-dependent two-electron reduction of nitric oxide (no) to nitrous oxide (n2o). while much progress has been made in biochemical and biophysical studies of native nors and their variants, a clear mechanistic understanding of this im ...	2015	26274098
from genome to structure and back again: a family portrait of the transcarbamylases.	enzymes in the transcarbamylase family catalyze the transfer of a carbamyl group from carbamyl phosphate (cp) to an amino group of a second substrate. the two best-characterized members, aspartate transcarbamylase (atcase) and ornithine transcarbamylase (otcase), are present in most organisms from bacteria to humans. recently, structures of four new transcarbamylase members, n-acetyl-l-ornithine transcarbamylase (aotcase), n-succinyl-l-ornithine transcarbamylase (sotcase), ygew encoded transcarb ...	2015	26274952
structural basis for the atp-dependent configuration of adenylation active site in bacillus subtilis o-succinylbenzoyl-coa synthetase.	o-succinylbenzoyl-coa synthetase, or mene, is an essential adenylate-forming enzyme targeted for development of novel antibiotics in the menaquinone biosynthesis. using its crystal structures in a ligand-free form or in complex with nucleotides, a conserved pattern is identified in the interaction between atp and adenylating enzymes, including acyl/aryl-coa synthetases, adenylation domains of nonribosomal peptide synthetases, and luciferases. it involves tight gripping interactions of the phosph ...	2015	26276389
knowledge-based discovery for designing crispr-cas systems against invading mobilomes in thermophiles.	clustered regularly interspaced short palindromic repeats (crisprs) are direct features of the prokaryotic genomes involved in resistance to their bacterial viruses and phages. herein, we have identified crispr loci together with crispr-associated sequences (cas) genes to reveal their immunity against genome invaders in the thermophilic archaea and bacteria. genomic survey of this study implied that genomic distribution of crispr-cas systems was varied from strain to strain, which was determined ...	2015	26279704
parametrization of macrolide antibiotics using the force field toolkit.	macrolides are an important class of antibiotics that target the bacterial ribosome. computer simulations of macrolides are limited as specific force field parameters have not been previously developed for them. here, we determine charmm-compatible force field parameters for erythromycin, azithromycin, and telithromycin, using the force field toolkit (fftk) plugin in vmd. because of their large size, novel approaches for parametrizing them had to be developed. two methods for determining partial ...	2015	26280362
physiological implications of arginine metabolism in plants.	nitrogen is a limiting resource for plant growth in most terrestrial habitats since large amounts of nitrogen are needed to synthesize nucleic acids and proteins. among the 21 proteinogenic amino acids, arginine has the highest nitrogen to carbon ratio, which makes it especially suitable as a storage form of organic nitrogen. synthesis in chloroplasts via ornithine is apparently the only operational pathway to provide arginine in plants, and the rate of arginine synthesis is tightly regulated by ...	2015	26284079
argonaute 2: a novel rising star in cancer research.	ago2 (argonaute 2, eif2c2) is the only member in ago family with catalytic activity and of extreme importance during small rnas guided gene silencing processes. the structural investigations have provided insights into details and functional mechanisms of the four major domains within ago2. as a multifunction player, ago2 has been revealed involved in tumorgenesis through mirnas-dependent or independent ways. and nowadays, ago2 has also been more importantly found ectopically over-expressed in c ...	2015	26284139
pyranopterin coordination controls molybdenum electrochemistry in escherichia coli nitrate reductase.	we test the hypothesis that pyranopterin (ppt) coordination plays a critical role in defining molybdenum active site redox chemistry and reactivity in the mononuclear molybdoenzymes. the molybdenum atom of escherichia coli nitrate reductase a (narghi) is coordinated by two ppt-dithiolene chelates that are defined as proximal and distal based on their proximity to a [4fe-4s] cluster known as fs0. we examined variants of two sets of residues involved in ppt coordination: (i) those interacting dire ...	2015	26297003
structure of ribosomal silencing factor bound to mycobacterium tuberculosis ribosome.	the ribosomal silencing factor rsfs slows cell growth by inhibiting protein synthesis during periods of diminished nutrient availability. the crystal structure of mycobacterium tuberculosis (mtb) rsfs, together with the cryo-electron microscopy (em) structure of the large subunit 50s of mtb ribosome, reveals how inhibition of protein synthesis by rsfs occurs. rsfs binds to the 50s at l14, which, when occupied, blocks the association of the small subunit 30s. although mtb rsfs is a dimer in solut ...	2015	26299947
functional characterization and expression analysis of rice δ(1)-pyrroline-5-carboxylate dehydrogenase provide new insight into the regulation of proline and arginine catabolism.	while intracellular proline accumulation in response to various stress conditions has been investigated in great detail, the biochemistry and physiological relevance of proline degradation in plants is much less understood. moreover, the second and last step in proline catabolism, the oxidation of δ(1)-pyrroline-5-carboxylic acid (p5c) to glutamate, is shared with arginine catabolism. little information is available to date concerning the regulatory mechanisms coordinating these two pathways. ex ...	2015	26300893
a unique uracil-dna binding protein of the uracil dna glycosylase superfamily.	uracil dna glycosylases (udgs) are an important group of dna repair enzymes, which pioneer the base excision repair pathway by recognizing and excising uracil from dna. based on two short conserved sequences (motifs a and b), udgs have been classified into six families. here we report a novel udg, udgx, from mycobacterium smegmatis and other organisms. udgx specifically recognizes uracil in dna, forms a tight complex stable to sodium dodecyl sulphate, 2-mercaptoethanol, urea and heat treatment, ...	2015	26304551
inhibition of human glut1 and glut5 by plant carbohydrate products; insights into transport specificity.	glucose transporters glut1 (transports glucose) and glut5 (transports fructose), in addition to their functions in normal metabolism, have been implicated in several diseases including cancer and diabetes. while glut1 has several inhibitors, none have been described for glut5. by transport activity assays we found two plant products, rubusoside (from rubus suavissimus) and astragalin-6-glucoside (a glycosylated derivative of astragalin, from phytolacca americana) that inhibited human glut5. thes ...	2015	26306809
crystal structure of staphylococcus aureus cas9.	the rna-guided dna endonuclease cas9 cleaves double-stranded dna targets with a protospacer adjacent motif (pam) and complementarity to the guide rna. recently, we harnessed staphylococcus aureus cas9 (sacas9), which is significantly smaller than streptococcus pyogenes cas9 (spcas9), to facilitate efficient in vivo genome editing. here, we report the crystal structures of sacas9 in complex with a single guide rna (sgrna) and its double-stranded dna targets, containing the 5'-ttgaat-3' pam and th ...	2015	26317473
plasmodium apicoplast gln-trnagln biosynthesis utilizes a unique gatab amidotransferase essential for erythrocytic stage parasites.	the malaria parasite plasmodium falciparum apicoplast indirect aminoacylation pathway utilizes a non-discriminating glutamyl-trna synthetase to synthesize glu-trna(gln) and a glutaminyl-trna amidotransferase to convert glu-trna(gln) to gln-trna(gln). here, we show that plasmodium falciparum and other apicomplexans possess a unique heterodimeric glutamyl-trna amidotransferase consisting of gata and gatb subunits (gatab). we localized the p. falciparum gata and gatb subunits to the apicoplast in b ...	2015	26318454
ribosome hibernation facilitates tolerance of stationary-phase bacteria to aminoglycosides.	upon entry into stationary phase, bacteria dimerize 70s ribosomes into translationally inactive 100s particles by a process called ribosome hibernation. previously, we reported that the hibernation-promoting factor (hpf) of listeria monocytogenes is required for 100s particle formation and facilitates adaptation to a number of stresses. here, we demonstrate that hpf is required for the high tolerance of stationary-phase cultures to aminoglycosides but not to beta-lactam or quinolone antibiotics. ...	2015	26324267
evidence for an induced conformational change in the catalytic mechanism of homoisocitrate dehydrogenase for saccharomyces cerevisiae: characterization of the d271n mutant enzyme.	homoisocitrate dehydrogenase (hicdh) catalyzes the nad(+)-dependent oxidative decarboxylation of hic to α-ketoadipate, the fourth step in the α-aminoadipate pathway responsible for the de novo synthesis of l-lysine in fungi. a mechanism has been proposed for the enzyme that makes use of a lys-tyr pair as acid-base catalysts, with lys acting as a base to accept a proton from the α-hydroxyl of homoisocitrate, and tyr acting as an acid to protonate the c3 of the enol of α-ketoadipate in the enoliza ...	2015	26325079
redox-induced activation of the proton pump in the respiratory complex i.	complex i functions as a redox-linked proton pump in the respiratory chains of mitochondria and bacteria, driven by the reduction of quinone (q) by nadh. remarkably, the distance between the q reduction site and the most distant proton channels extends nearly 200 å. to elucidate the molecular origin of this long-range coupling, we apply a combination of large-scale molecular simulations and a site-directed mutagenesis experiment of a key residue. in hybrid quantum mechanics/molecular mechanics s ...	2015	26330610
toward a whole-cell model of ribosome biogenesis: kinetic modeling of ssu assembly.	central to all life is the assembly of the ribosome: a coordinated process involving the hierarchical association of ribosomal proteins to the rnas forming the small and large ribosomal subunits. the process is further complicated by effects arising from the intracellular heterogeneous environment and the location of ribosomal operons within the cell. we provide a simplified model of ribosome biogenesis in slow-growing escherichia coli. kinetic models of in vitro small-subunit reconstitution at ...	2015	26333594
stay wet, stay stable? how internal water helps the stability of thermophilic proteins.	we present a systematic computational investigation of the internal hydration of a set of homologous proteins of different stability content and molecular complexities. the goal of the study is to verify whether structural water can be part of the molecular mechanisms ensuring enhanced stability in thermophilic enzymes. our free-energy calculations show that internal hydration in the thermophilic variants is generally more favorable, and that the cumulated effect of wetting multiple sites result ...	2015	26335353
essentiality of threonylcarbamoyladenosine (t(6)a), a universal trna modification, in bacteria.	threonylcarbamoyladenosine (t(6)a) is a modified nucleoside universally conserved in trnas in all three kingdoms of life. the recently discovered genes for t(6)a synthesis, including tsac and tsad, are essential in model prokaryotes but not essential in yeast. these genes had been identified as antibacterial targets even before their functions were known. however, the molecular basis for this prokaryotic-specific essentiality has remained a mystery. here, we show that t(6)a is a strong positive ...	2015	26337258
structures of archaeal dna segregation machinery reveal bacterial and eukaryotic linkages.	although recent studies have provided a wealth of information about archaeal biology, nothing is known about the molecular basis of dna segregation in these organisms. here, we unveil the machinery and assembly mechanism of the archaeal sulfolobus pnob8 partition system. this system uses three proteins: para; an atypical parb adaptor; and a centromere-binding component, aspa. aspa utilizes a spreading mechanism to create a dna superhelix onto which parb assembles. this supercomplex links to the ...	2015	26339031
the use of polyoxometalates in protein crystallography - an attempt to widen a well-known bottleneck.	polyoxometalates (poms) are discrete polynuclear metal-oxo anions with a fascinating variety of structures and unique chemical and physical properties. their application in various fields is well covered in the literature, however little information about their usage in protein crystallization is available. this review summarizes the impact of the vast class of poms on the formation of protein crystals, a well-known (frustrating) bottleneck in macromolecular crystallography, with the associated ...	2015	26339074
the landscape of intertwined associations in homooligomeric proteins.	we present an overview of the full repertoire of intertwined associations in homooligomeric proteins. this overview summarizes recent findings on the different categories of intertwined associations in known protein structures, their assembly modes, the properties of their interfaces, and their structural plasticity. furthermore, the current body of knowledge on the so-called three-dimensional domain-swapped systems is reexamined in the context of the wider landscape of intertwined homooligomers ...	2015	26340815
mechanisms of microrna turnover.	micrornas (mirnas) are 20-24 nucleotide (nt) rnas that regulate gene expression by guiding argonaute (ago) proteins to specific target rnas to cause their degradation or translational repression. the abundance of mirnas is strictly controlled at the transcriptional or post-transcriptional levels. mirna turnover is presumably a necessary means to regulate mirna levels in response to physiological, developmental, and environmental changes. mirna 3' end methylation, 3' end nucleotide addition, ago ...	2015	26342825
characterization of clinically identified mutations in ndufv1, the flavin-binding subunit of respiratory complex i, using a yeast model system.	dysfunctions in mitochondrial complex i (nadh:ubiquinone oxidoreductase) are both genetically and clinically highly diverse and a major cause of human mitochondrial diseases. the genetic determinants of individual clinical cases are increasingly being described, but how these genetic defects affect complex i on the molecular and cellular level, and have different clinical consequences in different individuals, is little understood. furthermore, without molecular-level information innocent geneti ...	2015	26345448
the presence of highly disruptive 16s rrna mutations in clinical samples indicates a wider role for mutations of the mitochondrial ribosome in human disease.	mitochondrial dna mutations are well recognized as an important cause of disease, with over two hundred variants in the protein encoding and mt-trna genes associated with human disorders. in contrast, the two genes encoding the mitochondrial rrnas (mt-rrnas) have been studied in far less detail. this is because establishing the pathogenicity of mt-rrna mutations is a major diagnostic challenge. only two disease causing mutations have been identified at these loci, both mapping to the small subun ...	2015	26349026
card uses a minor groove wedge mechanism to stabilize the rna polymerase open promoter complex.	a key point to regulate gene expression is at transcription initiation, and activators play a major role. card, an essential activator in mycobacterium tuberculosis, is found in many bacteria, including thermus species, but absent in escherichia coli. to delineate the molecular mechanism of card, we determined crystal structures of thermus transcription initiation complexes containing card. the structures show card interacts with the unique dna topology presented by the upstream double-stranded/ ...	2015	26349034
loop recognition and copper-mediated disulfide reduction underpin metal site assembly of cua in human cytochrome oxidase.	maturation of cytochrome oxidases is a complex process requiring assembly of several subunits and adequate uptake of the metal cofactors. two orthologous sco proteins (sco1 and sco2) are essential for the correct assembly of the dicopper cua site in the human oxidase, but their function is not fully understood. here, we report an in vitro biochemical study that shows that sco1 is a metallochaperone that selectively transfers cu(i) ions based on loop recognition, whereas sco2 is a copper-dependen ...	2015	26351686
binuclear cu(a) formation in biosynthetic models of cu(a) in azurin proceeds via a novel cu(cys)2his mononuclear copper intermediate.	cu(a) is a binuclear electron transfer (et) center found in cytochrome c oxidases (ccos), nitrous oxide reductases (n₂ors), and nitric oxide reductase (nor). in these proteins, the cu(a) centers facilitate efficient et (ket > 10⁴s⁻¹) under low thermodynamic driving forces (10-90 mv). while the structure and functional properties of cu(a) are well understood, a detailed mechanism of the incorporation of copper into the protein and the identity of the intermediates formed during the cu(a) maturati ...	2015	26352296
mismatch repair.	highly conserved muts homologs (msh) and mutl homologs (mlh/pms) are the fundamental components of mismatch repair (mmr). after decades of debate, it appears clear that the msh proteins initiate mmr by recognizing a mismatch and forming multiple extremely stable atp-bound sliding clamps that diffuse without hydrolysis along the adjacent dna. the function(s) of mlh/pms proteins is less clear, although they too bind atp and are targeted to mmr by msh sliding clamps. structural analysis combined wi ...	2015	26354434
a high-throughput assay for the comprehensive profiling of dna ligase fidelity.	dna ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. in order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates co ...	2015	26365241
a high-throughput assay for the comprehensive profiling of dna ligase fidelity.	dna ligases have broad application in molecular biology, from traditional cloning methods to modern synthetic biology and molecular diagnostics protocols. ligation-based detection of polynucleotide sequences can be achieved by the ligation of probe oligonucleotides when annealed to a complementary target sequence. in order to achieve a high sensitivity and low background, the ligase must efficiently join correctly base-paired substrates, while discriminating against the ligation of substrates co ...	2015	26365241
facial primer provides immediate and long-term improvements in mild-to-moderate facial hyperpigmentation and fine lines associated with photoaging.	photoaged skin results from various environmental factors, most importantly chronic sun exposure. dyschromia and fine lines/wrinkles are common clinical manifestations of photodamaged skin.	2015	26366102
structural basis for a unique atp synthase core complex from nanoarcheaum equitans.	atp synthesis is a critical and universal life process carried out by atp synthases. whereas eukaryotic and prokaryotic atp synthases are well characterized, archaeal atp synthases are relatively poorly understood. the hyperthermophilic archaeal parasite, nanoarcheaum equitans, lacks several subunits of the atp synthase and is suspected to be energetically dependent on its host, ignicoccus hospitalis. this suggests that this atp synthase might be a rudimentary machine. here, we report the crysta ...	2015	26370083
structure of subcomplex iβ of mammalian respiratory complex i leads to new supernumerary subunit assignments.	mitochondrial complex i (proton-pumping nadh:ubiquinone oxidoreductase) is an essential respiratory enzyme. mammalian complex i contains 45 subunits: 14 conserved "core" subunits and 31 "supernumerary" subunits. the structure of bos taurus complex i, determined to 5-å resolution by electron cryomicroscopy, described the structure of the mammalian core enzyme and allowed the assignment of 14 supernumerary subunits. here, we describe the 6.8-å resolution x-ray crystallography structure of subcompl ...	2015	26371297
protein-protein interfaces in viral capsids are structurally unique.	viral capsids exhibit elaborate and symmetrical architectures of defined sizes and remarkable mechanical properties not seen with cellular macromolecular complexes. given the uniqueness of the higher-order organization of viral capsid proteins in the virosphere, we explored the question of whether the patterns of protein-protein interactions within viral capsids are distinct from those in generic protein complexes. our comparative analysis involving a non-redundant set of 551 inter-subunit inter ...	2015	26375252
biochemical characterization and validation of a catalytic site of a highly thermostable ts2631 endolysin from the thermus scotoductus phage vb_tsc2631.	phage vb_tsc2631 infects the extremophilic bacterium thermus scotoductus mat2631 and uses the ts2631 endolysin for the release of its progeny. the ts2631 endolysin is the first endolysin from thermophilic bacteriophage with an experimentally validated catalytic site. in silico analysis and computational modelling of the ts2631 endolysin structure revealed a conserved zn2+ binding site (his30, tyr58, his131 and cys139) similar to zn2+ binding site of eukaryotic peptidoglycan recognition proteins ...	2015	26375388
directed evolution of the escherichia coli camp receptor protein at the camp pocket.	the escherichia coli camp receptor protein (crp) requires camp binding to undergo a conformational change for dna binding and transcriptional regulation. two crp residues, thr(127) and ser(128), are known to play important roles in camp binding through hydrogen bonding and in the camp-induced conformational change, but the connection between the two is not completely clear. here, we simultaneously randomized the codons for these two residues and selected crp mutants displaying high crp activity ...	2015	26378231
identification of middle chain fatty acyl-coa ligase responsible for the biosynthesis of 2-alkylmalonyl-coas for polyketide extender unit.	understanding the biosynthetic mechanism of the atypical polyketide extender unit is important for the development of bioactive natural products. reveromycin (rm) derivatives produced by streptomyces sp. sn-593 possess several aliphatic extender units. here, we studied the molecular basis of 2-alkylmalonyl-coa formation by analyzing the revr and revs genes, which form a transcriptional unit with the revt gene, a crotonyl-coa carboxylase/reductase homolog. we mainly focused on the uncharacterized ...	2015	26378232
epoxyqueuosine reductase structure suggests a mechanism for cobalamin-dependent trna modification.	queuosine (q) is a hypermodified rna base that replaces guanine in the wobble positions of 5'-gun-3' trna molecules. q is exclusively made by bacteria, and the corresponding queuine base is a micronutrient salvaged by eukaryotic species. the final step in q biosynthesis is the reduction of the epoxide precursor, epoxyqueuosine, to yield the q cyclopentene ring. the epoxyqueuosine reductase responsible, queg, shares distant homology with the cobalamin-dependent reductive dehalogenase (rdha), howe ...	2015	26378237
autophosphorylation of the bacterial tyrosine-kinase cpsd connects capsule synthesis with the cell cycle in streptococcus pneumoniae.	bacterial capsular polysaccharides (cps) are produced by a multi-protein membrane complex, in which a particular type of tyrosine-autokinases named by-kinases, regulate their polymerization and export. however, our understanding of the role of by-kinases in these processes remains incomplete. in the human pathogen streptococcus pneumoniae, the by-kinase cpsd localizes at the division site and participates in the proper assembly of the capsule. in this study, we show that the cytoplasmic c-termin ...	2015	26378458
structure of a human translation termination complex.	in contrast to bacteria that have two release factors, rf1 and rf2, eukaryotes only possess one unrelated release factor erf1, which recognizes all three stop codons of the mrna and hydrolyses the peptidyl-trna bond. while the molecular basis for bacterial termination has been elucidated, high-resolution structures of eukaryotic termination complexes have been lacking. here we present a 3.8 å structure of a human translation termination complex with erf1 decoding a uaa(a) stop codon. the complex ...	2015	26384426
coevolution of rtcb and archease created a multiple-turnover rna ligase.	rtcb is a noncanonical rna ligase that joins either 2',3'-cyclic phosphate or 3'-phosphate termini to 5'-hydroxyl termini. the genes encoding rtcb and archease constitute a trna splicing operon in many organisms. archease is a cofactor of rtcb that accelerates rna ligation and alters the ntp specificity of the ligase from pyrococcus horikoshii. yet, not all organisms that encode rtcb also encode archease. here we sought to understand the differences between archease-dependent and archease-indepe ...	2015	26385509
nascent chain-monitored remodeling of the sec machinery for salinity adaptation of marine bacteria.	secdf interacts with the secyeg translocon in bacteria and enhances protein export in a proton-motive-force-dependent manner. vibrio alginolyticus, a marine-estuarine bacterium, contains two secdf paralogs, v.secdf1 and v.secdf2. here, we show that the export-enhancing function of v.secdf1 requires na+ instead of h+, whereas v.secdf2 is na+-independent, presumably requiring h+. in accord with the cation-preference difference, v.secdf2 was only expressed under limited na+ concentrations whereas v ...	2015	26392525
simulating the function of sodium/proton antiporters.	the molecular basis of the function of transporters is a problem of significant importance, and the emerging structural information has not yet been converted to a full understanding of the corresponding function. this work explores the molecular origin of the function of the bacterial na+/h+ antiporter nhaa by evaluating the energetics of the na+ and h+ movement and then using the resulting landscape in monte carlo simulations that examine two transport models and explore which model can reprod ...	2015	26392528
suppression of capsule expression in δlon strains of escherichia coli by two novel rpob mutations in concert with hns: possible role for dna bending at rcsa promoter.	analyses of mutations in genes coding for subunits of rna polymerase always throw more light on the intricate events that regulate the expression of gene(s). lon protease of escherichia coli is implicated in the turnover of rcsa (positive regulator of genes involved in capsular polysaccharide synthesis) and sula (cell division inhibitor induced upon dna damage). failure to degrade rcsa and sula makes lon mutant cells to overproduce capsular polysaccharides and to become sensitive to dna damaging ...	2015	26403574
uncommon glycosidases for the enzymatic preparation of glycosides.	most of the reports in literature dedicated to the use of glycosyl hydrolases for the preparation of glycosides are about gluco- (α- and β-form) and galacto-sidase (β-form), reflecting the high-availability of both anomers of glucosides and of β-galactosides and their wide-ranging applications. hence, the idea of this review was to analyze the literature focusing on hardly-mentioned natural and engineered glycosyl hydrolases. their performances in the synthetic mode and natural hydrolytic potent ...	2015	26404386
flagellin glycosylation in paenibacillus alvei ccm 2051t.	flagellin glycosylation impacts, in several documented cases, the functionality of bacterial flagella. the basis of flagellin glycosylation has been studied for various gram-negative bacteria, but less is known about flagellin glycans of gram-positive bacteria including paenibacillus alvei, a secondary invader of honeybee colonies diseased with european foulbrood. paenibacillus alvei ccm 2051(t) swarms vigorously on solidified culture medium, with swarming relying on functional flagella as evide ...	2016	26405108
flagellin glycosylation in paenibacillus alvei ccm 2051t.	flagellin glycosylation impacts, in several documented cases, the functionality of bacterial flagella. the basis of flagellin glycosylation has been studied for various gram-negative bacteria, but less is known about flagellin glycans of gram-positive bacteria including paenibacillus alvei, a secondary invader of honeybee colonies diseased with european foulbrood. paenibacillus alvei ccm 2051(t) swarms vigorously on solidified culture medium, with swarming relying on functional flagella as evide ...	2016	26405108
recent insights into the structure, regulation, and function of the v-atpases.	the vacuolar (h(+))-atpases (v-atpases) are atp-dependent proton pumps that acidify intracellular compartments and are also present at the plasma membrane. they function in such processes as membrane traffic, protein degradation, virus and toxin entry, bone resorption, ph homeostasis, and tumor cell invasion. v-atpases are large multisubunit complexes, composed of an atp-hydrolytic domain (v1) and a proton translocation domain (v0), and operate by a rotary mechanism. this review focuses on recen ...	2015	26410601
ribosome structure reveals preservation of active sites in the presence of a p-site wobble mismatch.	translation initiation in the p site occasionally occurs at atypical (non-aug) start codons, including those forming a mismatch in the third (wobble) position. during elongation, however, a pyrimidine-pyrimidine wobble mismatch may trigger a translation quality-control mechanism, whereby the p-site mismatch is thought to perturb the downstream a-site codon or the decoding center, thereby reducing translation fidelity and inducing termination of aberrant translation. we report a crystal structure ...	2015	26412335
structural basis for gene regulation by a b12-dependent photoreceptor.	photoreceptor proteins enable organisms to sense and respond to light. the newly discovered carh-type photoreceptors use a vitamin b12 derivative, adenosylcobalamin, as the light-sensing chromophore to mediate light-dependent gene regulation. here we present crystal structures of thermus thermophilus carh in all three relevant states: in the dark, both free and bound to operator dna, and after light exposure. these structures provide visualizations of how adenosylcobalamin mediates carh tetramer ...	2015	26416754
affinity purification and structural features of the yeast vacuolar atpase vo membrane sector.	the membrane sector (vo) of the proton pumping vacuolar atpase (v-atpase, v1vo-atpase) from saccharomyces cerevisiae was purified to homogeneity, and its structure was characterized by em of single molecules and two-dimensional crystals. projection images of negatively stained vo two-dimensional crystals showed a ring-like structure with a large asymmetric mass at the periphery of the ring. a cryo-em reconstruction of vo from single-particle images showed subunits a and d in close contact on the ...	2015	26416888
cpf1 is a single rna-guided endonuclease of a class 2 crispr-cas system.	the microbial adaptive immune system crispr mediates defense against foreign genetic elements through two classes of rna-guided nuclease effectors. class 1 effectors utilize multi-protein complexes, whereas class 2 effectors rely on single-component effector proteins such as the well-characterized cas9. here, we report characterization of cpf1, a putative class 2 crispr effector. we demonstrate that cpf1 mediates robust dna interference with features distinct from cas9. cpf1 is a single rna-guid ...	2015	26422227
variation in the ribosome interacting loop of the sec61α from giardia lamblia.	the interaction between the ribosome and the endoplasmic reticulum-located sec61 protein translocon is mediated through an arginine residue of sec61α, which is conserved in all prokaryotic and eukaryotic orthologues characterized to date. using in silico approaches we report that instead of arginine, this ribosome-interaction function is most likely discharged by a lysine residue in the protist giardia lamblia. this functional substitution of the r with a k in glsec61α may have taken place to ac ...	2015	26424409
an extended dsrbd is required for post-transcriptional modification in human trnas.	in trna, dihydrouridine is a conserved modified base generated by the post-transcriptional reduction of uridine. formation of dihydrouridine 20, located in the d-loop, is catalyzed by dihydrouridine synthase 2 (dus2). human dus2 (hsdus2) expression is upregulated in lung cancers, offering a growth advantage throughout its ability to interact with components of the translation apparatus and inhibit apoptosis. here, we report the crystal structure of the individual domains of hsdus2 and their func ...	2015	26429968
membrane protein structures without crystals, by single particle electron cryomicroscopy.	it is an exciting period in membrane protein structural biology with a number of medically important protein structures determined at a rapid pace. however, two major hurdles still remain in the structural biology of membrane proteins. one is the inability to obtain large amounts of protein for crystallization and the other is the failure to get well-diffracting crystals. with single particle electron cryomicroscopy, both these problems can be overcome and high-resolution structures of membrane ...	2015	26435463
a particular silent codon exchange in a recombinant gene greatly influences host cell metabolic activity.	recombinant protein production using escherichia coli as expression host is highly efficient, however, it also induces strong host cell metabolic burden. energy and biomass precursors are withdrawn from the host's metabolism as they are required for plasmid replication, heterologous gene expression and protein production. rare codons in a heterologous gene may be a further drawback. this study aims to investigate the influence of particular silent codon exchanges within a heterologous gene on ho ...	2015	26438243
long-term survival of borrelia burgdorferi lacking the hibernation promotion factor homolog in the unfed tick vector.	borrelia burgdorferi, a causative agent of lyme borreliosis, is a zoonotic pathogen that survives in nutrient-limited environments within a tick, prior to transmission to its mammalian host. survival under these prolonged nutrient-limited conditions is thought to be similar to survival during stationary phase, which is characterized by growth cessation and decreased protein production. multiple ribosome-associated proteins are implicated in stationary-phase survival of escherichia coli. these pr ...	2015	26438790
ion-pumping microbial rhodopsins.	rhodopsins are light-sensing proteins used in optogenetics. the word "rhodopsin" originates from the greek words "rhodo" and "opsis," indicating rose and sight, respectively. although the classical meaning of rhodopsin is the red-colored pigment in our eyes, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. animal and microbial rhodopsins possess 11-cis and all-trans retinal, respectively, to capture light in seven transmem ...	2015	26442282
the dna exonucleases of escherichia coli.	dna exonucleases, enzymes that hydrolyze phosphodiester bonds in dna from a free end, play important cellular roles in dna repair, genetic recombination and mutation avoidance in all organisms. this article reviews the structure, biochemistry, and biological functions of the 17 exonucleases currently identified in the bacterium escherichia coli. these include the exonucleases associated with dna polymerases i (pola), ii (polb), and iii (dnaq/mutd); exonucleases i (xona/sbcb), iii (xtha), iv, vii ...	2011	26442508
biosynthesis of pantothenic acid and coenzyme a.	pantothenate is vitamin b5 and is the key precursor for the biosynthesis of coenzyme a (coa), a universal and essential cofactor involved in a myriad of metabolic reactions, including the synthesis of phospholipids, the synthesis and degradation of fatty acids, and the operation of the tricarboxylic acid cycle. coa is also the only source of the phosphopantetheine prosthetic group for enzymes that shuttle intermediates between the active sites of enzymes involved in fatty acid, nonribosomal pept ...	2007	26443589
biogenesis and homeostasis of nicotinamide adenine dinucleotide cofactor.	universal and ubiquitous redox cofactors, nicotinamide adenine dinucleotide (nad) and its phosphorylated analog (nadp), collectively contribute to approximately 12% of all biochemical reactions included in the metabolic model of escherichia coli k-12. a homeostasis of the nad pool faithfully maintained by the cells results from a dynamic balance in a network of nad biosynthesis, utilization, decomposition, and recycling pathways that is subject to tight regulation at various levels. a brief over ...	2009	26443758
an s6:s18 complex inhibits translation of e. coli rpsf.	more than half of the ribosomal protein operons in escherichia coli are regulated by structures within the mrna transcripts that interact with specific ribosomal proteins to inhibit further protein expression. this regulation is accomplished using a variety of mechanisms and the rna structures responsible for regulation are often not conserved across bacterial phyla. a widely conserved mrna structure preceding the ribosomal protein operon containing rpsf and rpsr (encoding s6 and s18) was recent ...	2015	26447183
intrastrand triplex dna repeats in bacteria: a source of genomic instability.	repetitive nucleic acid sequences are often prone to form secondary structures distinct from b-dna. prominent examples of such structures are dna triplexes. we observed that certain intrastrand triplex motifs are highly conserved and abundant in prokaryotic genomes. a systematic search of 5246 different prokaryotic plasmids and genomes for intrastrand triplex motifs was conducted and the results summarized in the itxf database available online at http://bioinformatics.uni-konstanz.de/utils/itxf/ ...	2015	26450966
the 29(th) annual symposium of the protein society, barcelona, spain, july 22-25, 2015.		2015	26452528
structural insight into fungal cell wall recognition by a cvnh protein with a single lysm domain.	mgg_03307 is a lectin isolated from magnaporte oryzae, a fungus that causes devastating rice blast disease. its function is associated with protecting m. oryzae from the host immune response in plants. to provide the structural basis of how mgg_03307 protects the fungus, crystal structures of its cvnh-lysm module were determined in the absence and presence of glcnac-containing cell wall chitin constituents, which can act as pathogen-associated molecular patterns. our structures revealed that gly ...	2015	26455798
fr171456 is a specific inhibitor of mammalian nsdhl and yeast erg26p.	fr171456 is a natural product with cholesterol-lowering properties in animal models, but its molecular target is unknown, which hinders further drug development. here we show that fr171456 specifically targets the sterol-4-alpha-carboxylate-3-dehydrogenase (saccharomyces cerevisiae--erg26p, homo sapiens--nsdhl (nad(p) dependent steroid dehydrogenase-like)), an essential enzyme in the ergosterol/cholesterol biosynthesis pathway. fr171456 significantly alters the levels of cholesterol pathway inte ...	2015	26456460
complete genome sequence of the thermophilic thermus sp. ccb_us3_uf1 from a hot spring in malaysia.	thermus sp. strain ccb_us3_uf1 is a thermophilic bacterium of the genus thermus, a member of the family thermaceae. members of the genus thermus have been widely used as a biological model for structural biology studies and to understand the mechanism of microbial adaptation under thermal environments. here, we present the complete genome sequence of thermus sp. ccb_us3_uf1 isolated from a hot spring in malaysia, which is the fifth member of the genus thermus with a completely sequenced and publ ...	2015	26457128
functional importance of mobile ribosomal proteins.	although the dynamic motions and peptidyl transferase activity seem to be embedded in the rrnas, the ribosome contains more than 50 ribosomal proteins (r-proteins), whose functions remain largely elusive. also, the precise forms of some of these r-proteins, as being part of the ribosome, are not structurally solved due to their high flexibility, which hinders the efforts in their functional elucidation. owing to recent advances in cryo-electron microscopy, single-molecule techniques, and theoret ...	2015	26457300
acoustic vibrations contribute to the diffuse scatter produced by ribosome crystals.	the diffuse scattering pattern produced by frozen crystals of the 70s ribosome from thermus thermophilus is as highly structured as it would be if it resulted entirely from domain-scale motions within these particles. however, the qualitative properties of the scattering pattern suggest that acoustic displacements of the crystal lattice make a major contribution to it.	2015	26457426
high-resolution structures of lactobacillus salivarius transketolase in the presence and absence of thiamine pyrophosphate.	probiotic bacterial strains have been shown to enhance the health of the host through a range of mechanisms including colonization, resistance against pathogens, secretion of antimicrobial compounds and modulation of the activity of the innate immune system. lactobacillus salivarius ucc118 is a well characterized probiotic strain which survives intestinal transit and has many desirable host-interaction properties. probiotic bacteria display a wide range of catabolic activities, which determine t ...	2015	26457526
structural analysis of nucleosomal barrier to transcription.	thousands of human and drosophila genes are regulated at the level of transcript elongation and nucleosomes are likely targets for this regulation. however, the molecular mechanisms of formation of the nucleosomal barrier to transcribing rna polymerase ii (pol ii) and nucleosome survival during/after transcription remain unknown. here we show that both dna-histone interactions and pol ii backtracking contribute to formation of the barrier and that nucleosome survival during transcription likely ...	2015	26460019
caenorhabditis elegans glp-4 encodes a valyl aminoacyl trna synthetase.	germline stem cell proliferation is necessary to populate the germline with sufficient numbers of cells for gametogenesis and for signaling the soma to control organismal properties such as aging. the caenorhabditis elegans gene glp-4 was identified by the temperature-sensitive allele bn2 where mutants raised at the restrictive temperature produce adults that are essentially germ cell deficient, containing only a small number of stem cells arrested in the mitotic cycle but otherwise have a morph ...	2015	26464357
crystallographic characterization of the ribosomal binding site and molecular mechanism of action of hygromycin a.	hygromycin a (hyga) binds to the large ribosomal subunit and inhibits its peptidyl transferase (pt) activity. the presented structural and biochemical data indicate that hyga does not interfere with the initial binding of aminoacyl-trna to the a site, but prevents its subsequent adjustment such that it fails to act as a substrate in the pt reaction. structurally we demonstrate that hyga binds within the peptidyl transferase center (ptc) and induces a unique conformation. specifically in its ribo ...	2015	26464437
structural insights into species-specific features of the ribosome from the pathogen staphylococcus aureus.	the emergence of bacterial multidrug resistance to antibiotics threatens to cause regression to the preantibiotic era. here we present the crystal structure of the large ribosomal subunit from staphylococcus aureus, a versatile gram-positive aggressive pathogen, and its complexes with the known antibiotics linezolid and telithromycin, as well as with a new, highly potent pleuromutilin derivative, bc-3205. these crystal structures shed light on specific structural motifs of the s. aureus ribosome ...	2015	26464510
complete genome sequence of thermus aquaticus y51mc23.	thermus aquaticus y51mc23 was isolated from a boiling spring in the lower geyser basin of yellowstone national park. remarkably, this t. aquaticus strain is able to grow anaerobically and produces multiple morphological forms. y51mc23 is a gram-negative, rod-shaped organism that grows well between 50°c and 80°c with maximum growth rate at 65°c to 70°c. growth studies suggest that y51mc23 primarily scavenges protein from the environment, supported by the high number of secreted and intracellular ...	2015	26465632
crystal structure of the human trna m(1)a58 methyltransferase-trna(3)(lys) complex: refolding of substrate trna allows access to the methylation target.	human trna3(lys) is the primer for reverse transcription of hiv; the 3' end is complementary to the primer-binding site on hiv rna. the complementarity ends at the 18th base, a58, which in trna3(lys) is modified to remove watson-crick pairing. motivated to test the role of the modification in terminating the primer-binding sequence and thus limiting run-on transcription, we asked how the modification of rna could be accomplished. trna m(1)a58 methyltransferase (m(1)a58 mtase) methylates n1 of a5 ...	2015	26470919
activities of the peptidyl transferase center of ribosomes lacking protein l27.	the ribosome is the molecular machine responsible for protein synthesis in all living organisms. its catalytic core, the peptidyl transferase center (ptc), is built of rrna, although several proteins reach close to the inner rrna shell. in the escherichia coli ribosome, the flexible n-terminal tail of the ribosomal protein l27 contacts the a- and p-site trna. based on computer simulations of the ptc and on previous biochemical evidence, the n-terminal α-amino group of l27 was suggested to take p ...	2015	26475831
mechanism of eif6 release from the nascent 60s ribosomal subunit.	sbds protein (deficient in the inherited leukemia-predisposition disorder shwachman-diamond syndrome) and the gtpase efl1 (an ef-g homolog) activate nascent 60s ribosomal subunits for translation by catalyzing eviction of the antiassociation factor eif6 from nascent 60s ribosomal subunits. however, the mechanism is completely unknown. here, we present cryo-em structures of human sbds and sbds-efl1 bound to dictyostelium discoideum 60s ribosomal subunits with and without endogenous eif6. sbds ass ...	2015	26479198