Publications

conservation of coevolving protein interfaces bridges prokaryote-eukaryote homologies in the twilight zone.	protein-protein interactions are fundamental for the proper functioning of the cell. as a result, protein interaction surfaces are subject to strong evolutionary constraints. recent developments have shown that residue coevolution provides accurate predictions of heterodimeric protein interfaces from sequence information. so far these approaches have been limited to the analysis of families of prokaryotic complexes for which large multiple sequence alignments of homologous sequences can be compi ...	2016	27965389
vapcs of mycobacterium tuberculosis cleave rnas essential for translation.	the major human pathogen mycobacterium tuberculosis can survive in the host organism for decades without causing symptoms. a large cohort of toxin-antitoxin (ta) modules contribute to this persistence. of these, 48 ta modules belong to the vapbc (virulence associated protein) gene family. vapc toxins are pin domain endonucleases that, in enterobacteria, inhibit translation by site-specific cleavage of initiator trna. in contrast, vapc20 of m. tuberculosis inhibits translation by site-specific cl ...	2016	27599842
global association between thermophilicity and vancomycin susceptibility in bacteria.	exploration of the aquatic microbiota of several circum-neutral (6.0-8.5 ph) mid-temperature (55-85°c) springs revealed rich diversities of phylogenetic relatives of mesophilic bacteria, which surpassed the diversity of the truly-thermophilic taxa. to gain insight into the potentially-thermophilic adaptations of the phylogenetic relatives of gram-negative mesophilic bacteria detected in culture-independent investigations we attempted pure-culture isolation by supplementing the enrichment media w ...	2016	27065976
comparing residue clusters from thermophilic and mesophilic enzymes reveals adaptive mechanisms.	understanding how proteins adapt to function at high temperatures is important for deciphering the energetics that dictate protein stability and folding. while multiple principles important for thermostability have been identified, we lack a unified understanding of how internal protein structural and chemical environment determine qualitative or quantitative impact of evolutionary mutations. in this work we compare equivalent clusters of spatially neighboring residues between paired thermophili ...	2016	26741367
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
the novel aminomethylcycline omadacycline has high specificity for the primary tetracycline-binding site on the bacterial ribosome.	omadacycline is an aminomethylcycline antibiotic with potent activity against many gram-positive and gram-negative pathogens, including strains carrying the major efflux and ribosome protection resistance determinants. this makes it a promising candidate for therapy of severe infectious diseases. omadacycline inhibits bacterial protein biosynthesis and competes with tetracycline for binding to the ribosome. its interactions with the 70s ribosome were, therefore, analyzed in great detail and comp ...	2016	27669321
crispr-mediated epigenome editing.	mounting evidence has called into question our understanding of the role that the central dogma of molecular biology plays in human pathology. the conventional view that elucidating the mechanisms for translating genes into proteins can account for a panoply of diseases has proven incomplete. landmark studies point to epigenetics as a missing piece of the puzzle. however, technological limitations have hindered the study of specific roles for histone post-translational modifications, dna modific ...	2016	28018139
a comprehensive benchmarking study of protocols and sequencing platforms for 16s rrna community profiling.	in the last 5 years, the rapid pace of innovations and improvements in sequencing technologies has completely changed the landscape of metagenomic and metagenetic experiments. therefore, it is critical to benchmark the various methodologies for interrogating the composition of microbial communities, so that we can assess their strengths and limitations. the most common phylogenetic marker for microbial community diversity studies is the 16s ribosomal rna gene and in the last 10 years the field h ...	2016	26763898
chloramphenicol derivatives as antibacterial and anticancer agents: historic problems and current solutions.	chloramphenicol (cam) is the d-threo isomer of a small molecule, consisting of a p-nitrobenzene ring connected to a dichloroacetyl tail through a 2-amino-1,3-propanediol moiety. cam displays a broad-spectrum bacteriostatic activity by specifically inhibiting the bacterial protein synthesis. in certain but important cases, it also exhibits bactericidal activity, namely against the three most common causes of meningitis, haemophilus influenzae, streptococcus pneumoniae and neisseria meningitidis. ...	2016	27271676
crystal structure of cota laccase complexed with 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) at a novel binding site.	the cota laccase from bacillus subtilis is an abundant component of the spore outer coat and has been characterized as a typical laccase. the crystal structure of cota complexed with 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (abts) in a hole motif has been solved. the novel binding site was about 26 å away from the t1 binding pocket. comparison with known structures of other laccases revealed that the hole is a specific feature of cota. the key residues arg476 and ser360 were directly bo ...	2016	27050268
metagenomic insights into the uncultured diversity and physiology of microbes in four hypersaline soda lake brines.	soda lakes are salt lakes with a naturally alkaline ph due to evaporative concentration of sodium carbonates in the absence of major divalent cations. hypersaline soda brines harbor microbial communities with a high species- and strain-level archaeal diversity and a large proportion of still uncultured poly-extremophiles compared to neutral brines of similar salinities. we present the first "metagenomic snapshots" of microbial communities thriving in the brines of four shallow soda lakes from th ...	2016	26941731
discovery and structural characterisation of new fold type iv-transaminases exemplify the diversity of this enzyme fold.	transaminases are useful biocatalysts for the production of amino acids and chiral amines as intermediates for a broad range of drugs and fine chemicals. here, we describe the discovery and characterisation of new transaminases from microorganisms which were enriched in selective media containing (r)-amines as sole nitrogen source. while most of the candidate proteins were clearly assigned to known subgroups of the fold iv family of plp-dependent enzymes by sequence analysis and characterisation ...	2016	27905516
new insight into isoprenoids biosynthesis process and future prospects for drug designing in plasmodium.	the mep (methyl erythritol phosphate) isoprenoids biosynthesis pathway is an attractive drug target to combat malaria, due to its uniqueness and indispensability for the parasite. it is functional in the apicoplast of plasmodium and its products get transported to the cytoplasm, where they participate in glycoprotein synthesis, electron transport chain, trna modification and several other biological processes. several compounds have been tested against the enzymes involved in this pathway and am ...	2016	27679614
identification and characterization of the novel subunit ccom in the cbb3₃cytochrome c oxidase from pseudomonas stutzeri zobell.	cytochrome c oxidases (ccos), members of the heme-copper containing oxidase (hco) superfamily, are the terminal enzymes of aerobic respiratory chains. the cbb3-type cytochrome c oxidases (cbb3-cco) form the c-family and have only the central catalytic subunit in common with the a- and b-family hcos. in pseudomonas stutzeri, two cbb3 operons are organized in a tandem repeat. the atomic structure of the first cbb3 isoform (cbb3-1) was determined at 3.2 å resolution in 2010 (s. buschmann, e. warken ...	2016	26814183
in situ spectroscopy reveals that microorganisms in different phyla use different electron transfer biomolecules to respire aerobically on soluble iron.	absorbance spectra were collected on 12 different live microorganisms, representing six phyla, as they respired aerobically on soluble iron at ph 1.5. a novel integrating cavity absorption meter was employed that permitted accurate absorbance measurements in turbid suspensions that scattered light. illumination of each microorganism yielded a characteristic spectrum of electrochemically reduced colored prosthetic groups. a total of six different patterns of reduced-minus-oxidized difference spec ...	2016	28008327
distribution and dynamics of electron transport complexes in cyanobacterial thylakoid membranes.	the cyanobacterial thylakoid membrane represents a system that can carry out both oxygenic photosynthesis and respiration simultaneously. the organization, interactions and mobility of components of these two electron transport pathways are indispensable to the biosynthesis of thylakoid membrane modules and the optimization of bioenergetic electron flow in response to environmental changes. these are of fundamental importance to the metabolic robustness and plasticity of cyanobacteria. this revi ...	2016	26619924
convergent evolution of trna gene targeting preferences in compact genomes.	in gene-dense genomes, mobile elements are confronted with highly selective pressure to amplify without causing excessive damage to the host. the targeting of trna genes as potentially safe integration sites has been developed by retrotransposons in various organisms such as the social amoeba dictyostelium discoideum and the yeast saccharomyces cerevisiae. in d. discoideum, trna gene-targeting retrotransposons have expanded to approximately 3 % of the genome. recently obtained genome sequences o ...	2016	27583033
ribosomal frameshifting and transcriptional slippage: from genetic steganography and cryptography to adventitious use.	genetic decoding is not 'frozen' as was earlier thought, but dynamic. one facet of this is frameshifting that often results in synthesis of a c-terminal region encoded by a new frame. ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational 'correction' of problem or 'savior' indels. utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. one class of re ...	2016	27436286
comparative transcriptomics across the prokaryotic tree of life.	whole-transcriptome sequencing studies from recent years revealed an unexpected complexity in transcriptomes of bacteria and archaea, including abundant non-coding rnas, cis-antisense transcription and regulatory untranslated regions (utrs). understanding the functional relevance of the plethora of non-coding rnas in a given organism is challenging, especially since some of these rnas were attributed to 'transcriptional noise'. to allow the search for conserved transcriptomic elements we produce ...	2016	27154273
bacterial rna polymerase-dna interaction-the driving force of gene expression and the target for drug action.	dna-dependent multisubunit rna polymerase (rnap) is the key enzyme of gene expression and a target of regulation in all kingdoms of life. it is a complex multifunctional molecular machine which, unlike other dna-binding proteins, engages in extensive and dynamic interactions (both specific and nonspecific) with dna, and maintains them over a distance. these interactions are controlled by dna sequences, dna topology, and a host of regulatory factors. here, we summarize key recent structural and b ...	2016	27882317
bacterial transcription as a target for antibacterial drug development.	transcription, the first step of gene expression, is carried out by the enzyme rna polymerase (rnap) and is regulated through interaction with a series of protein transcription factors. rnap and its associated transcription factors are highly conserved across the bacterial domain and represent excellent targets for broad-spectrum antibacterial agent discovery. despite the numerous antibiotics on the market, there are only two series currently approved that target transcription. the determination ...	2016	26764017
cryo-em structures of the autoinhibited e. coli atp synthase in three rotational states.	a molecular model that provides a framework for interpreting the wealth of functional information obtained on the e. coli f-atp synthase has been generated using cryo-electron microscopy. three different states that relate to rotation of the enzyme were observed, with the central stalk's ε subunit in an extended autoinhibitory conformation in all three states. the fo motor comprises of seven transmembrane helices and a decameric c-ring and invaginations on either side of the membrane indicate th ...	2016	28001127
energy conversion, redox catalysis and generation of reactive oxygen species by respiratory complex i.	complex i (nadh:ubiquinone oxidoreductase) is critical for respiration in mammalian mitochondria. it oxidizes nadh produced by the krebs' tricarboxylic acid cycle and β-oxidation of fatty acids, reduces ubiquinone, and transports protons to contribute to the proton-motive force across the inner membrane. complex i is also a significant contributor to cellular oxidative stress. in complex i, nadh oxidation by a flavin mononucleotide, followed by intramolecular electron transfer along a chain of i ...	2016	26721206
characterization of the nqo5 subunit of bacterial complex i in the isolated state.	the subunits that comprise bacterial complex i (nadh:ubiquinone oxidoreductase) are also found in more complicated mitochondrial enzymes in eukaryotic organisms. although the nqo5 subunit is one of these conserved components and important for the formation of complex, it has been little studied. here, we report structure analyses of isolated nqo5 from thermus thermophilus. biochemical studies indicated that the c-terminal region following the 30-kd subunit motif is disordered in the isolated sta ...	2016	27398308
evidence for fast electron transfer between the high-spin haems in cytochrome bd-i from escherichia coli.	cytochrome bd-i is one of the three proton motive force-generating quinol oxidases in the o2-dependent respiratory chain of escherichia coli. it contains one low-spin haem (b558) and the two high-spin haems (b595 and d) as the redox-active cofactors. in order to examine the flash-induced intraprotein reverse electron transfer (the so-called ''electron backflow''), co was photolyzed from the ferrous haem d in one-electron reduced (b5583+b5953+d2+-co) cytochrome bd-i, and the fully reduced (b5582+ ...	2016	27152644
different functions of phylogenetically distinct bacterial complex i isozymes.	nadh:quinone oxidoreductase (complex i) is a bioenergetic enzyme that transfers electrons from nadh to quinone, conserving the energy of this reaction by contributing to the proton motive force. while the importance of nadh oxidation to mitochondrial aerobic respiration is well documented, the contribution of complex i to bacterial electron transport chains has been tested in only a few species. here, we analyze the function of two phylogenetically distinct complex i isozymes in rhodobacter spha ...	2016	26833419
investigating the proton donor in the no reductase from paracoccus denitrificans.	variant nomenclature: the variants were made in the norb subunit if not indicated by the superscript c, which are variants in the norc subunit (e.g. e122a = exchange of glu-122 in norb for an ala, e71cd; exchange of glu-71 in norc for an asp). bacterial no reductases (nors) are integral membrane proteins from the heme-copper oxidase superfamily. most heme-copper oxidases are proton-pumping enzymes that reduce o2 as the last step in the respiratory chain. with electrons from cytochrome c, no redu ...	2016	27030968
models for the a subunits of the thermus thermophilus v/a-atpase and saccharomyces cerevisiae v-atpase enzymes by cryo-em and evolutionary covariance.	rotary atpases couple atp synthesis or hydrolysis to proton translocation across a membrane. however, understanding proton translocation has been hampered by a lack of structural information for the membrane-embedded a subunit. the v/a-atpase from the eubacterium thermus thermophilus is similar in structure to the eukaryotic v-atpase but has a simpler subunit composition and functions in vivo to synthesize atp rather than pump protons. we determined the t. thermophilus v/a-atpase structure by cr ...	2016	26951669
cysteine biosynthesis in lactobacillus casei: identification and characterization of a serine acetyltransferase.	in bacteria, cysteine can be synthesized from serine by two steps involving an l-serine o-acetyltransferase (sat) and a cysteine synthase (cysk). while cysk is found in the publicly available annotated genome from lactobacillus casei atcc 334, a gene encoding sat (cyse) is missing. in this study, we found that various strains of l. casei grew in a chemically defined medium containing sulfide as the sole sulfur source, indicating the presence of a serine o-acetyltransferase. the gene lying upstre ...	2016	26790714
trueprime is a novel method for whole-genome amplification from single cells based on tthprimpol.	sequencing of a single-cell genome requires dna amplification, a process prone to introducing bias and errors into the amplified genome. here we introduce a novel multiple displacement amplification (mda) method based on the unique dna primase features of thermus thermophilus (tth) primpol. tthprimpol displays a potent primase activity preferring dntps as substrates unlike conventional primases. a combination of tthprimpol's unique ability to synthesize dna primers with the highly processive phi ...	2016	27897270
high-resolution phenotypic landscape of the rna polymerase ii trigger loop.	the active sites of multisubunit rna polymerases have a "trigger loop" (tl) that multitasks in substrate selection, catalysis, and translocation. to dissect the saccharomyces cerevisiae rna polymerase ii tl at individual-residue resolution, we quantitatively phenotyped nearly all tl single variants en masse. three mutant classes, revealed by phenotypes linked to transcription defects or various stresses, have distinct distributions among tl residues. we find that mutations disrupting an intra-tl ...	2016	27898685
adaptation in bacillus cereus: from stress to disease.	bacillus cereus is a food-borne pathogen that causes diarrheal disease in humans. after ingestion, b. cereus experiences in the human gastro-intestinal tract abiotic physical variables encountered in food, such as acidic ph in the stomach and changing oxygen conditions in the human intestine. b. cereus responds to environmental changing conditions (stress) by reversibly adjusting its physiology to maximize resource utilization while maintaining structural and genetic integrity by repairing and m ...	2016	27757102
origin of a folded repeat protein from an intrinsically disordered ancestor.	repetitive proteins are thought to have arisen through the amplification of subdomain-sized peptides. many of these originated in a non-repetitive context as cofactors of rna-based replication and catalysis, and required the rna to assume their active conformation. in search of the origins of one of the most widespread repeat protein families, the tetratricopeptide repeat (tpr), we identified several potential homologs of its repeated helical hairpin in non-repetitive proteins, including the put ...	2016	27623012
visualizing the phage t4 activated transcription complex of dna and e. coli rna polymerase.	the ability of rna polymerase (rnap) to select the right promoter sequence at the right time is fundamental to the control of gene expression in all organisms. however, there is only one crystallized structure of a complete activator/rnap/dna complex. in a process called σ appropriation, bacteriophage t4 activates a class of phage promoters using an activator (mota) and a co-activator (asia), which function through interactions with the σ(70) subunit of rnap. we have developed a holistic, struct ...	2016	27458207
cold shock proteins: a minireview with special emphasis on csp-family of enteropathogenic yersinia.	bacteria have evolved a number of mechanisms for coping with stress and adapting to changing environmental conditions. many bacteria produce small cold shock proteins (csp) as a response to rapid temperature downshift (cold shock). during cold shock, the cell membrane fluidity and enzyme activity decrease, and the efficiency of transcription and translation is reduced due to stabilization of nucleic acid secondary structures. moreover, protein folding is inefficient and ribosome function is hamp ...	2016	27499753
application of a euryarchaeota-specific helicase from thermococcus kodakarensis for noise reduction in pcr.	dna/rna helicases, which are enzymes for eliminating hydrogen bonds between bases of dna/dna, dna/rna, and rna/rna using the energy of atp hydrolysis, contribute to various biological activities. in the present study, the euryarchaeota-specific helicase esha (tk0566) from the hyperthermophilic archaeon thermococcus kodakarensis (tk-esha) was obtained as a recombinant form, and its enzymatic properties were examined. tk-esha exhibited maximal atpase activity in the presence of rna at 80°c. unwind ...	2016	26969705
mycobacterium tuberculosis transcription machinery: ready to respond to host attacks.	regulating responses to stress is critical for all bacteria, whether they are environmental, commensal, or pathogenic species. for pathogenic bacteria, successful colonization and survival in the host are dependent on adaptation to diverse conditions imposed by the host tissue architecture and the immune response. once the bacterium senses a hostile environment, it must enact a change in physiology that contributes to the organism's survival strategy. inappropriate responses have consequences; h ...	2016	26883824
structures of e. coli σs-transcription initiation complexes provide new insights into polymerase mechanism.	in bacteria, multiple σ factors compete to associate with the rna polymerase (rnap) core enzyme to form a holoenzyme that is required for promoter recognition. during transcription initiation rnap remains associated with the upstream promoter dna via sequence-specific interactions between the σ factor and the promoter dna while moving downstream for rna synthesis. as rna polymerase repetitively adds nucleotides to the 3'-end of the rna, a pyrophosphate ion is generated after each nucleotide inco ...	2016	27035955
illumina error profiles: resolving fine-scale variation in metagenomic sequencing data.	illumina's sequencing platforms are currently the most utilised sequencing systems worldwide. the technology has rapidly evolved over recent years and provides high throughput at low costs with increasing read-lengths and true paired-end reads. however, data from any sequencing technology contains noise and our understanding of the peculiarities and sequencing errors encountered in illumina data has lagged behind this rapid development.	2016	26968756
the inhibitory effect of non-substrate and substrate dna on the ligation and self-adenylylation reactions catalyzed by t4 dna ligase.	dna ligases are essential both to in vivo replication, repair and recombination processes, and in vitro molecular biology protocols. prior characterization of dna ligases through gel shift assays has shown the presence of a nick site to be essential for tight binding between the enzyme and its dsdna substrate, with no interaction evident on dsdna lacking a nick. in the current study, we observed a significant substrate inhibition effect, as well as the inhibition of both the self-adenylylation a ...	2016	26954034
physiological properties and genome structure of the hyperthermophilic filamentous phage φoh3 which infects thermus thermophilus hb8.	a filamentous bacteriophage, φoh3, was isolated from hot spring sediment in obama hot spring in japan with the hyperthermophilic bacterium thermus thermophilus hb8 as its host. phage φoh3, which was classified into the inoviridae family, consists of a flexible filamentous particle 830 nm long and 8 nm wide. φoh3 was stable at temperatures ranging from 70 to 90°c and at phs ranging from 6 to 9. a one-step growth curve of the phage showed a 60-min latent period beginning immediately postinfection, ...	2016	26941711
single-cell-genomics-facilitated read binning of candidate phylum em19 genomes from geothermal spring metagenomes.	the vast majority of microbial life remains uncatalogued due to the inability to cultivate these organisms in the laboratory. this "microbial dark matter" represents a substantial portion of the tree of life and of the populations that contribute to chemical cycling in many ecosystems. in this work, we leveraged an existing single-cell genomic data set representing the candidate bacterial phylum "calescamantes" (em19) to calibrate machine learning algorithms and define metagenomic bins directly ...	2016	26637598
mutations in the nucleotide binding and hydrolysis domains of helicobacter pylori muts2 lead to altered biochemical activities and inactivation of its in vivo function.	helicobacter pylori muts2 (hpmuts2), an inhibitor of recombination during transformation is a non-specific nuclease with two catalytic sites, both of which are essential for its anti-recombinase activity. although hpmuts2 belongs to a highly conserved family of abc transporter atpases, the role of its atp binding and hydrolysis activities remains elusive.	2016	26843368
lineage-specific variations in the trigger loop modulate rna proofreading by bacterial rna polymerases.	rna cleavage by bacterial rna polymerase (rnap) has been implicated in transcriptional proofreading and reactivation of arrested transcription elongation complexes but its molecular mechanism is less understood than the mechanism of nucleotide addition, despite both reactions taking place in the same active site. rnap from the radioresistant bacterium deinococcus radiodurans is characterized by highly efficient intrinsic rna cleavage in comparison with escherichia coli rnap. we find that the enh ...	2016	26733581
amylose recognition and ring-size determination of amylomaltase.	starch is a major carbon and energy source throughout all kingdoms of life. it consists of two carbohydrate polymers, branched amylopectin and linear amylose, which are sparingly soluble in water. hence, the enzymatic breakdown by glycoside hydrolases (ghs) is of great biological and societal importance. amylomaltases (ams) are ghs specialized in the hydrolysis of α-1,4-linked sugar chains such as amylose. they are able to catalyze an intramolecular transglycosylation of a bound sugar chain yiel ...	2017	28097217
an ambiguity principle for assigning protein structural domains.	ambiguity is the quality of being open to several interpretations. for an image, it arises when the contained elements can be delimited in two or more distinct ways, which may cause confusion. we postulate that it also applies to the analysis of protein three-dimensional structure, which consists in dividing the molecule into subunits called domains. because different definitions of what constitutes a domain can be used to partition a given structure, the same protein may have different but equa ...	2017	28097215
integrating mass spectrometry with md simulations reveals the role of lipids in na(+)/h(+) antiporters.	na(+)/h(+) antiporters are found in all kingdoms of life and exhibit catalysis rates that are among the fastest of all known secondary-active transporters. here we combine ion mobility mass spectrometry and molecular dynamics simulations to study the conformational stability and lipid-binding properties of the na(+)/h(+) exchanger napa from thermus thermophilus and compare this to the prototypical antiporter nhaa from escherichia coli and the human homologue nha2. we find that napa and nha2, but ...	2017	28071645
exploring conformational equilibria of a heterodimeric abc transporter.	abc exporters pump substrates across the membrane by coupling atp-driven movements of nucleotide binding domains (nbds) to the transmembrane domains (tmds), which switch between inward- and outward-facing (if, of) orientations. deer measurements on the heterodimeric abc exporter tm287/288 from thermotoga maritima, which contains a non-canonical atp binding site, revealed that in the presence of nucleotides the transporter exists in an if/of equilibrium. while atp binding was sufficient to partia ...	2017	28051765
thermophilic bacteria are potential sources of novel rieske non-heme iron oxygenases.	rieske non-heme iron oxygenases, which have a rieske-type [2fe-2s] cluster and a non-heme catalytic iron center, are an important family of oxidoreductases involved mainly in regio- and stereoselective transformation of a wide array of aromatic hydrocarbons. though present in all domains of life, the most widely studied rieske non-heme iron oxygenases are found in mesophilic bacteria. the present study explores the potential for isolating novel rieske non-heme iron oxygenases from thermophilic s ...	2017	28050858
activation of respiratory complex i from escherichia coli studied by fluorescent probes.	respiratory complex i from e. coli may exist in two interconverting forms: resting (r) and active (a). the r/a transition of purified, solubilized complex i occurring upon turnover was studied employing two different fluorescent probes, annine 6+, and ndb-acetogenin. nadh-induced fluorescent changes of both dyes bound to solubilized complex i from e. coli were characterized as a function of the protein:dye ratio, temperature, ubiquinone redox state and the enzyme activity. analysis of this data ...	2017	28070565