# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 528 | 0 | 1.0000 | Effect of dimethyl sulphoxide on the expression of nitrogen fixation in bacteria. Storage in dimethyl sulphoxide (DMSO) of Escherichia coli K12 hybrids carrying nif+ genes from Klebsiella pneumoniae can result in selection of a defective nitrogen-fixing phenotype. Similar results are obtained with E. coli K12 hybrids containing the nitrogen-fixing capacity from Rhizobium trifolii. DMSO appears to affect particular inner membrane proteins associated with energy metabolism in E. coli K12 and four chromosomal regions (chlD, chlG, his and unc) are associated with resistance to DMSO. | 1977 | 332135 |
| 337 | 1 | 0.9966 | Effect of nifA product on suppression of Nif- phenotype of gln mutation and constitutive synthesis of nitrogenase in Klebsiella pneumoniae. This paper describes the role of nifA product on the ammonia regulation of nitrogen fixation in K. pneumoniae. A plasmid carrying nifA gene under the promoter of tetracycline resistance gene was constructed. When this nifA carrying plasmid was introduced into a glnAG mutant, the Nif- phenotype of this gln mutant was suppressed. Furthermore, when the plasmid was introduced into the wild type and glnAG mutant, derepression of nitrogenase synthesis in ammonia occurred in both strains and the products of nif genes can be detected by two-dimensional gel electrophoresis in the extracts of these ammonia-grown bacterial cells. The constitutive synthesis of nitrogenase in NH4+ was also demonstrated in free living nitrogen-fixing bacteria, Enterobacter cloacae, when the bacteria received the plasmid carrying nifA gene from K. pneumoniae. | 1983 | 6143398 |
| 555 | 2 | 0.9956 | Mutations in dsbA and dsbB, but not dsbC, lead to an enhanced sensitivity of Escherichia coli to Hg2+ and Cd2+. The Dsb proteins are involved in disulfide bond formation, reduction and isomerisation in a number of Gram-negative bacteria. Mutations in dsbA or dsbB, but not dsbC, increase the proportion of proteins with free thiols in the periplasm compared to wild-type. We investigated the effects of mutations in these genes on the bacterial resistance to mercuric and cadmium salts. Mutations in genes involved primarily in disulfide formation (dsbA and dsbB) generally enhanced the sensitivity to Hg2+ and Cd2+ while a mutation of the dsbC gene (primarily an isomerase of disulfide bonds) had no effect. Mutations of the dsb genes had no effect on the expression of the mercury-resistance determinants of the transposon Tn501. | 1999 | 10234837 |
| 347 | 3 | 0.9954 | A novel plasmid gene involved in bacteriophage PRD1 infection and conjugative host-range. PRD1 infects bacteria carrying IncN plasmids by binding to their conjugative pili. Mutations in a plasmid locus kikA close to the pilus region result in PRD1 resistance and reduced conjugation proficiency to Klebsiella but not to Escherichia coli. One of the two genes of kikA is sufficient to restore both normal phenotypes. PRD1 binds to cells carrying the mutant plasmid but fails to inject its genome. | 1996 | 8812786 |
| 344 | 4 | 0.9953 | Identification of genes in Rhizobium leguminosarum bv. trifolii whose products are homologues to a family of ATP-binding proteins. The specific interaction between rhizobia and their hosts requires many genes that influence both early and late steps in symbiosis. Three new genes, designated prsD, prsE (protein secretion) and orf3, were identified adjacent to the exo133 mutation in a cosmid carrying the genomic DNA of Rhizobium leguminosarum bv. trifolii TA1. The prsDE genes share significant homology to the genes encoding ABC transporter proteins PrtDE from Erwinia chrysanthemi and AprDE from Pseudomonas aeruginosa which export the proteases in these bacteria. PrsD shows at least five potential transmembrane hydrophobic regions and a large hydrophilic domain containing an ATP/GTP binding cassette. PrsE has only one potential transmembrane hydrophobic domain in the N-terminal part and is proposed to function as an accessory factor in the transport system. ORF3, like PrtF and AprF, has a typical N-terminal signal sequence but has no homology to these proteins. The insertion of a kanamycin resistance cassette into the prsD gene of the R. leguminosarum bv. trifolii TA1 wild-type strain created a mutant which produced a normal amount of exopolysaccharide but was not effective in the nodulation of clover plants. | 1997 | 9141701 |
| 341 | 5 | 0.9951 | UV resistance of E. coli K-12 deficient in cAMP/CRP regulation. Deletion of genes for adenylate cyclase (delta cya) or cAMP receptor protein (delta crp) in E. coli K-12 confers a phenotype that includes resistance to UV radiation (254 nm). Such mutations lead to UV resistance of uvr+, uvrA, lexA and recA strains which could partly be abolished by the addition of cAMP to delta cya but not to delta crp strain culture medium. This effect was not related to either inducibility of major DNA repair genes or growth rate of the bacteria. Enhanced survival was also observed for UV-irradiated lambda bacteriophage indicating that a repair mechanism of UV lesions was involved in this phenomenon. | 1992 | 1379686 |
| 576 | 6 | 0.9950 | Caenorhabditis elegans defective-pharynx and constipated mutants are resistant to Orsay virus infection. C. elegans animals with a compromised pharynx accumulate bacteria in their intestinal lumen and activate a transcriptional response that includes anti-bacterial response genes. In this study, we demonstrate that animals with defective pharynxes are resistant to Orsay virus (OrV) infection. This resistance is observed for animals grown on Escherichia coli OP50 and on Comamonas BIGb0172, a bacterium naturally associated with C. elegans . The viral resistance observed in defective-pharynx mutants does not seem to result from constitutive transcriptional immune responses against viruses. OrV resistance is also observed in mutants with defective defecation, which share with the pharynx-defective perturbations in the regulation of their intestinal contents and altered lipid metabolism. The underlying mechanisms of viral resistance in pharynx- and defecation-defective mutants remain elusive. | 2024 | 38590801 |
| 6090 | 7 | 0.9950 | Draft genome sequence of Mesorhizobium alhagi CCNWXJ12-2T, a novel salt-resistant species isolated from the desert of northwestern China. Mesorhizobium alhagi strain CCNWXJ12-2(T) is a novel species of soil-dwelling, nitrogen-fixing bacteria that can form symbiotic root nodules with Alhagi sparsifolia. Moreover, the strain has high resistance to salt and alkali. Here we report the draft genome sequence of Mesorhizobium alhagi strain CCNWXJ12-2(T). A large number of osmotic regulation-related genes have been identified. | 2012 | 22328758 |
| 287 | 8 | 0.9949 | Reversion of mutations in the thymidine kinase gene in herpes simplex viruses resistant to phosphonoacetate. Mutations in the DNA polymerase locus of phage, bacteria, and eukaryotic may change the mutation rates at other loci of the genome. We used resistance to phosphonoacetate to select mutants of herpes simplex virus with mutated DNA polymerase and then determined the reversion frequency of viral thymidine kinase mutation in mutants and recombinants. The results obtained indicate that mutations causing resistance to phosphonoacetate do not affect the mutation rate of the viral genes. This finding is consistent with the existence of two functional regions in the DNA polymerase molecule, one involving the pyrophosphate acceptor site and responsible for resistance to phosphonoacetate and another involved in the editing ability and recognition specificity of the enzyme. | 1984 | 6331620 |
| 592 | 9 | 0.9949 | Metabolism of Tryptophan and Tryptophan Analogs by Rhizobium meliloti. The alfalfa symbiont Rhizobium meliloti Rm1021 produces indole-3-acetic acid in a regulated manner when supplied with exogenous tryptophan. Mutants with altered response to tryptophan analogs still produce indole-3-acetic acid, but are Fix(-) because bacteria do not fully differentiate into the nitrogen-fixing bacteriod form. These mutations are in apparently essential genes tightly linked to a dominant streptomycin resistance locus. | 1990 | 16667364 |
| 186 | 10 | 0.9948 | Plasmid-encoded resistance to arsenic and antimony. Resistance determinants to the toxic oxyanionic salts of arsenic and antimony are found on plasmids of both gram-negative and gram-positive organisms. In most cases these provide resistance to both the oxyanions of +III oxidation state, antimonite and arsenite, and the +V oxidation state, arsenate. In both gram-positive and -negative bacteria, resistance is correlated with efflux of the anions from cells. The determinant from the plasmid R773, isolated from a gram-negative organism, has been studied in detail. It encodes an oxyanion-translocating ATPase with three subunits, a catalytic subunit, the ArsA protein, a membrane subunit, the ArsB subunit, and a specificity factor, the ArsC protein. The first two form a membrane-bound complex with arsenite-stimulated ATPase activity. The determinants from gram-positive bacteria have only the arsB and arsC genes and encode an efflux system without the participation of an ArsA homologue. | 1992 | 1531541 |
| 162 | 11 | 0.9948 | Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acids in bacteria. The current knowledge on the structure and on the organization of polyhydroxyalkanoic acid (PHA)-biosynthetic genes from a wide range of different bacteria, which rely on different pathways for biosynthesis of this storage polyesters, is provided. Molecular data will be shown for genes of Alcaligenes eutrophus, purple non-sulfur bacteria, such as Rhodospirillum rubrum, purple sulfur bacteria, such as Chromatium vinosum, pseudomonads belonging to rRNA homology group I, such as Pseudomonas aeruginosa, Methylobacterium extorquens, and for the Gram-positive bacterium Rhodococcus ruber. Three different types of PHA synthases can be distinguished with respect to their substrate specificity and structure. Strategies for the cloning of PHA synthase structural genes will be outlined which are based on the knowledge of conserved regions of PHA synthase structural genes and of the PHA-biosynthetic routes in bacteria as well as on the heterologous expression of these genes and on the availability of mutants impaired in the accumulation of PHA. In addition, a terminology for the designation of PHAs and of proteins and genes relevant for the metabolism of PHA is suggested. | 1992 | 1476773 |
| 572 | 12 | 0.9947 | The RSP_2889 gene product of Rhodobacter sphaeroides is a CueR homologue controlling copper-responsive genes. Metal homeostasis is important in all living cells in order to provide sufficient amounts of metal ions for biological processes but to prevent toxic effects by excess amounts. Here we show that the gene product of RSP_2889 of the facultatively photosynthetic bacterium Rhodobacter sphaeroides is homologous to CueR, a regulator of copper metabolism in Escherichia coli and other bacteria. CueR binds to the promoter regions of genes for a copper-translocating ATPase and for a copper chaperone and is responsible for their high expression when cells are exposed to elevated levels of copper ions. While deletion of RSP_2889 has no significant effect on copper resistance, expression from a low-copy-number plasmid mediates increased sensitivity to copper. | 2011 | 21903751 |
| 388 | 13 | 0.9947 | Improved bacterial hosts for regulated expression of genes from lambda pL plasmid vectors. The construction and use of a set of Escherichia coli strains with defective lambda prophages that facilitate expression of genes cloned in lambda pL-plasmid vectors is described. These bacteria allow high and regulated expression of such genes, whereas a kanamycin-resistance marker (KmR) on the prophage allows easy identification and genetic transfer from strain to strain. Optimal conditions for examining gene expression with the pL-vector systems using these strains are discussed. | 1993 | 8406046 |
| 6184 | 14 | 0.9947 | Active efflux as a mechanism of resistance to ciprofloxacin in Streptococcus pneumoniae. The accumulation of fluoroquinolones (FQs) was studied in a FQ-susceptible laboratory strain of Streptococcus pneumoniae (strain R6). Uptake of FQs was not saturable, was rapidly reversible, and appeared to occur by passive diffusion. In the presence of glucose, which energizes bacteria, the uptake of FQs decreased. Inhibitors of the proton motive force and ATP synthesis increased the uptake of FQs in previously energized bacteria. Similar results were observed with the various FQs tested and may be explained to be a consequence simply of the pH gradient that exists across the cytoplasmic membrane. From a clinical susceptible strain (strain SPn5907) we isolated in vitro on ciprofloxacin an FQ-resistant mutant (strain SPn5929) for which the MICs of hydrophilic molecules were greater than those of hydrophobic molecules, and the mutant was resistant to acriflavine, cetrimide, and ethidium bromide. Strain SPn5929 showed a significantly decreased uptake of ciprofloxacin, and its determinant of resistance to ciprofloxacin was transferred by transformation to susceptible laboratory strain R6 (strain R6tr5929). No mutations in the quinolone resistance-determining regions of the gyrA and parC genes were found. In the presence of arsenate or carbonyl cyanide m-chlorophenylhydrazone, the levels of uptake of ciprofloxacin by the two resistant strains, SPn5929 and R6tr5929, reached the levels of uptake of their susceptible parents. These results suggest an active efflux of ciprofloxacin in strain SPn5929. | 1997 | 9303396 |
| 653 | 15 | 0.9946 | Connecting Algal Polysaccharide Degradation to Formaldehyde Detoxification. Formaldehyde is a toxic metabolite that is formed in large quantities during bacterial utilization of the methoxy sugar 6-O-methyl-d-galactose, an abundant monosaccharide in the red algal polysaccharide porphyran. Marine bacteria capable of metabolizing porphyran must therefore possess suitable detoxification systems for formaldehyde. We demonstrate here that detoxification of formaldehyde in the marine Flavobacterium Zobellia galactanivorans proceeds via the ribulose monophosphate pathway. Simultaneously, we show that the genes encoding the key enzymes of this pathway are important for maintaining high formaldehyde resistance. Additionally, these genes are upregulated in the presence of porphyran, allowing us to connect porphyran degradation to the detoxification of formed formaldehyde. | 2022 | 35561127 |
| 367 | 16 | 0.9946 | Translocatable resistance to mercuric and phenylmercuric ions in soil bacteria. Of a sample of 42 gram-negative Hg-resistant bacteria, three (a Pseudomonas fluorescens, a Klebsiella sp. and a Citrobacter sp.) contained translocatable elements conferring resistance to Hg2+ (all three) and to Hg2+ and phenylmercuric acetate (P. fluorescens). The discovery of transposable phenylmercuric acetate resistance extends the range of known resistance "transposons" from heavy metals and antibiotics to organometallic compounds. | 1981 | 6268601 |
| 8815 | 17 | 0.9946 | Phosphorus-Solubilizing Bacteria Enhance Cadmium Immobilization and Gene Expression in Wheat Roots to Reduce Cadmium Uptake. The application of phosphorus-solubilizing bacteria is an effective method for increasing the available phosphorus content and inhibiting wheat uptake of heavy metals. However, further research is needed on the mechanism by which phosphorus-solubilizing bacteria inhibit cadmium (Cd) uptake in wheat roots and its impact on the expression of root-related genes. Here, the effects of strain Klebsiella aerogenes M2 on Cd absorption in wheat and the expression of root-related Cd detoxification and immobilization genes were determined. Compared with the control, strain M2 reduced (64.1-64.6%) Cd uptake by wheat roots. Cd fluorescence staining revealed that strain M2 blocked the entry of exogenous Cd into the root interior and enhanced the immobilization of Cd by cell walls. Forty-seven genes related to Cd detoxification, including genes encoding peroxidase, chalcone synthase, and naringenin 3-dioxygenase, were upregulated in the Cd+M2 treatment. Strain M2 enhanced the Cd resistance and detoxification activity of wheat roots through the regulation of flavonoid biosynthesis and antioxidant enzyme activity. Moreover, strain M2 regulated the expression of genes related to phenylalanine metabolism and the MAPK signaling pathway to enhance Cd immobilization in roots. These results provide a theoretical basis for the use of phosphorus-solubilizing bacteria to remediate Cd-contaminated fields and reduce Cd uptake in wheat. | 2024 | 39065516 |
| 6179 | 18 | 0.9946 | Structures of Class I and Class II Transcription Complexes Reveal the Molecular Basis of RamA-Dependent Transcription Activation. Transcription activator RamA is linked to multidrug resistance of Klebsiella pneumoniae through controlling genes that encode efflux pumps (acrA) and porin-regulating antisense RNA (micF). In bacteria, σ(70) , together with activators, controls the majority of genes by recruiting RNA polymerase (RNAP) to the promoter regions. RNAP and σ(70) form a holoenzyme that recognizes -35 and -10 promoter DNA consensus sites. Many activators bind upstream from the holoenzyme and can be broadly divided into two classes. RamA acts as a class I activator on acrA and class II activator on micF, respectively. The authors present biochemical and structural data on RamA in complex with RNAP-σ(70) at the two promoters and the data reveal the molecular basis for how RamA assembles and interacts with core RNAP and activates transcription that contributes to antibiotic resistance. Further, comparing with CAP/TAP complexes reveals common and activator-specific features in activator binding and uncovers distinct roles of the two C-terminal domains of RNAP α subunit. | 2022 | 34761556 |
| 6231 | 19 | 0.9946 | NMR structure and calcium-binding properties of the tellurite resistance protein TerD from Klebsiella pneumoniae. The tellurium oxyanion TeO(3)(2-) has been used in the treatment of infectious diseases caused by mycobacteria. However, many pathogenic bacteria show tellurite resistance. Several tellurite resistance genes have been identified, and these genes mediate responses to diverse extracellular stimuli, but the mechanisms underlying their functions are unknown. To shed light on the function of KP-TerD, a 20.5 -kDa tellurite resistance protein from a plasmid of Klebsiella pneumoniae, we have determined its three-dimensional structure in solution using NMR spectroscopy. KP-TerD contains a β-sandwich formed by two five-stranded β-sheets and six short helices. The structure exhibits two negative clusters in loop regions on the top of the sandwich, suggesting that KP-TerD may bind metal ions. Indeed, thermal denaturation experiments monitored by circular dichroism and NMR studies reveal that KP-TerD binds Ca(2+). Inductively coupled plasma-optical emission spectroscopy shows that the binding ratio of KP-TerD to Ca(2+) is 1:2. EDTA (ethylenediaminetetraacetic acid) titrations of Ca(2+)-saturated KP-TerD monitored by one-dimensional NMR yield estimated dissociation constants of 18 and 200 nM for the two Ca(2+)-binding sites of KP-TerD. NMR structures incorporating two Ca(2+) ions define a novel bipartite Ca(2)(+)-binding motif that is predicted to be highly conserved in TerD proteins. Moreover, these Ca(2+)-binding sites are also predicted to be present in two additional tellurite resistance proteins, TerE and TerZ. These results suggest that some form of Ca(2+) signaling plays a crucial role in tellurite resistance and in other responses of bacteria to multiple external stimuli that depend on the Ter genes. | 2011 | 21112337 |