Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nucleotide sequences of two genes involved in sodium dodecyl sulfate (SDS) degradation, by Pseudomonas, have been determined. One of these, sdsA, codes for an alkyl sulfatase (58,957 Da) and has similarity (31.8% identity over a 201-amino acid stretch) to the N terminus of a predicted protein of unknown function from Mycobacterium tuberculosis. The other gene, sdsB, codes for a positive activator protein (33,600 Da) that has extensive similarity with the lysR family of helix-turn-helix DNA-binding activator proteins.
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PMID:Cloning and sequencing of Pseudomonas genes determining sodium dodecyl sulfate biodegradation. 158 81

We have previously described sigma A and sigma B and their structural genes, mysA and mysB, respectively, in Mycobacterium smegmatis. We have now sequenced the corresponding regions in the M. tuberculosis and M. leprae chromosomes, and have found the two homologous genes. The chromosomal linkage and the deduced amino acid (aa) sequences of the two genes show very high similarity in the three species of mycobacteria. We also report the finding of two other open reading frames (ORF) in these clusters. orfX, which has an unknown function, is located between mysA and mysB. The other ORF, located downstream from mysB, encodes a homolog of DtxR, the iron regulatory protein from Corynebacterium diphtheriae (Cd).
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PMID:Genomic organization of the mycobacterial sigma gene cluster. 748 18

A Bacillus Calmette Guerlin (BCG) DNA fragment was identified which conferred hypersensitivity to isoniazid (INH) upon Mycobacterium smegmatis (Ms) when present on a multicopy plasmid. The gene cluster present on this fragment contains the genes encoding ribosomal proteins L36 (rpmJ), S13 (rpsM), S11 (rpsK) and S4 (rpsD), as well as the gene encoding initiation factor-1 (infA), an open reading frame of unknown function (ORFX) and a putative promoter region. The rpsM gene, from either BCG or Ms is necessary and sufficient to produce the INH-hypersensitive phenotype in Ms, but the gene cluster has no effect on INH sensitivity when introduced into BCG on a multicopy plasmid. The presence of rpsM on a multicopy plasmid also causes an increase in catalase/peroxidase (Kat/Prx) activity in Ms. The overproduction of S13 may induce a stress response, resulting in increased expression of katG (encoding Kat/Prx) in Ms, thereby causing hypersensitivity to INH.
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PMID:Overproduction of mycobacterial ribosomal protein S13 induces catalase/peroxidase activity and hypersensitivity to isoniazid in Mycobacterium smegmatis. 862 Oct 83

Acinetobacter calcoaceticus BD413 accumulates wax esters and triacylglycerol under conditions of mineral nutrient limitation. Nitrosoguanidine-induced mutants of strain BD413 were isolated that failed to accumulate wax esters under nitrogen-limited growth conditions. One of the mutants, Wow15 (without wax), accumulated wax when grown in the presence of cis-11-hexadecenal and hexadecanol but not hexadecane or hexadecanoic acid. This suggested that the mutation may have inactivated a gene encoding either an acyl-acyl carrier protein or acyl-coenzyme A (CoA) reductase. The Wow15 mutant was complemented with a cosmid genomic library prepared from wild-type A. calcoaceticus BD413. The complementary region was localized to a single gene (acr1) encoding a protein of 32,468 Da that is 44% identical over a region of 264 amino acids to a product of unknown function encoded by an open reading frame associated with mycolic acid synthesis in Mycobacterium tuberculosis H37Ra. Extracts of Escherichia coli cells expressing the acr1 gene catalyzed the reduction of acyl-CoA to the corresponding fatty aldehyde, indicating that the gene encodes a novel fatty acyl-CoA reductase.
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PMID:Isolation of mutants of Acinetobacter calcoaceticus deficient in wax ester synthesis and complementation of one mutation with a gene encoding a fatty acyl coenzyme A reductase. 913 16

Aspergillus nidulans conidiospores contain high levels of the non-reducing disaccharide trehalose. We show that upon induction of conidiospore germination, the trehalose pool is rapidly degraded and a glycerol pool is transiently accumulated. A trehalase with an acidic pH optimum was purified from conidiospores. Characterization of the treA gene encoding this trehalase shows that it is homologous to Saccharomyces cerevisiae vacuolar acid trehalase, the product of the ATH1 gene, and to two related proteins of unknown function identified in Mycobacterium tuberculosis and Mycobacterium leprae. A. nidulans mutants that lack acid trehalase activity were constructed by gene replacement at the treA locus. Analysis of these mutants suggests that the treA gene product is localized in the conidiospore wall, is required for growth on trehalose as a carbon source, and is not involved in the mobilization of the intracellular pool of trehalose. Therefore, it is proposed that a cytoplasmic regulatory trehalase is controlling this latter process.
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PMID:Molecular characterization of the Aspergillus nidulans treA gene encoding an acid trehalase required for growth on trehalose. 914 Sep 77

A luminescence-based procedure that permits the rapid evaluation of the survival of mycobacteria within mononuclear phagocytes was developed and used to screen insertional mutants of Mycobacterium smegmatis for their ability to survive in human monocyte-derived macrophages. Among the 5000 mutants tested, eight mutants were identified that demonstrated impaired intracellular survival in human macrophages but that grew normally in the absence of cells. For each mutant, a portion of the gene interrupted by the transposition event was amplified by ligand-mediated PCR and sequenced. In all cases, the existence of homologous genes of as yet unknown function were identified in the Mycobacterium tuberculosis genome. Complementation of the mutant mycobacterial strains with cosmids containing the homologous loci from M. tuberculosis restored normal intracellular growth in three of the four mutants tested, supporting the idea that these loci contain genes that are important for intracellular survival. This study demonstrates the feasibility of directly screening mutant mycobacterial strains to identify genes coding for activities necessary for the intracellular survival in human mononuclear phagocytes, an important initial step in the identification of potential targets for new therapeutic agents.
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PMID:Identification of genetic loci implicated in the survival of Mycobacterium smegmatis in human mononuclear phagocytes. 972 Aug 65

A recombinant plasmid isolated from a Mycobacterium fortuitum genomic library by selection for gentamicin and 2-N'-ethylnetilmicin resistance conferred low-level aminoglycoside and tetracycline resistance when introduced into M. smegmatis. Further characterization of this plasmid allowed the identification of the M. fortuitum tap gene. A homologous gene in the M. tuberculosis H37Rv genome has been identified. The M. tuberculosis tap gene (Rv1258 in the annotated sequence of the M. tuberculosis genome) was cloned and conferred low-level resistance to tetracycline when introduced into M. smegmatis. The sequences of the putative Tap proteins showed 20 to 30% amino acid identity to membrane efflux pumps of the major facilitator superfamily (MFS), mainly tetracycline and macrolide efflux pumps, and to other proteins of unknown function but with similar antibiotic resistance patterns. Approximately 12 transmembrane regions and different sequence motifs characteristic of the MFS proteins also were detected. In the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone (CCCP), the levels of resistance to antibiotics conferred by plasmids containing the tap genes were decreased. When tetracycline accumulation experiments were carried out with the M. fortuitum tap gene, the level of tetracycline accumulation was lower than that in control cells but was independent of the presence of CCCP. We conclude that the Tap proteins of the opportunistic organism M. fortuitum and the important pathogen M. tuberculosis are probably proton-dependent efflux pumps, although we cannot exclude the possibility that they act as regulatory proteins.
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PMID:Molecular cloning and characterization of Tap, a putative multidrug efflux pump present in Mycobacterium fortuitum and Mycobacterium tuberculosis. 981 39

Forty-two protein spots of observed M(r) 6-15 kDa were resolved by two-dimensional gel electrophoresis, stained by Coomassie blue and subjected to Edman microsequencing. All of the proteins could be related back to their encoding open reading frames, thereby vindicating the bioinformatic tools currently utilised in their identification. However, only 14/42 gene-products were expressed as annotated. Translation was confirmed for 14 open reading frames with no attributed function (EcoGene Y-entries), while N-terminal sequence allowed the start codon to be accurately annotated for the genes yigF, yccU, yqiC, ynfD, and yeeX. The methionine start codon was cleaved in 11 gene-products (AtpE, Hns, RpoZ, RplL, CspC, YccJ, YggX, YjgF, HimA, InfA, RpsQ) and a further five showed loss of a signal peptide (PspE, HdeB, HdeA, YnfD, YkfE). Internal (Tig, AtpA, TufA) and N-terminal fragmentation (CspD, RpsF, AtcU) of much larger proteins was also detected, which may have resulted from physiological or translational processes. M(r) and pI isoforms were detected respectively for PtsH and GatB, each being phosphoproteins, as well as RplY which manifested differences with respect to predicted M(r) and pI. In addition, YjgF was shown to belong to a small gene family of unknown function with ancient conserved regions across procaryotes and eucaryotes. YgiN was revealed to have a paralogue and orthologues in Bacillus subtilis, Synechocystis sp., Mycobacterium tuberculosis, Neisseria gonorrhoea, and Rhodococcus erythropolis. Orthologues are also reported for YihD, YccU and YeeX. Of the 14 Y-genes, only YkfE possessed no detectable orthologues. These results highlight the need to complement genomic analysis with detailed proteomics in order to gain a better understanding of cellular molecular biology, while the confirmation of the open reading frame start codon using Edman degradation protein microsequencing has yet to be superseded by recent advances in mass spectrometry.
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PMID:Small genes/gene-products in Escherichia coli K-12. 986 84

RNA arbitrarily-primed differential display PCR (RAP-PCR) was used to identify and isolate genes differentially expressed between attenuated (H37Ra) and virulent (H37Rv, Erdman) laboratory strains of Mycobacterium tuberculosis (Mtb). Using this method, cDNA fragments showing homology to three known mycobacterial genes and six putative novel genes in mycobacterial cosmid vectors were identified. Among the putative novel Mtb genes identified, we found: (1) gene MTV041.29, containing multiple tandem repetitive sequences and encoding a putative Gly-, Ala, Asn-rich protein (PPE family); (2) gene MTV004.03, containing the AT10S repetitive gene sequence; (3) gene MTV028.09, encoding a hypothetical protein of unknown function; (4) genes MTCY78.20,21, possibly encoding two hypothetical proteins of unknown function; (5) gene MTCY01A6.09, encoding a putative novel ferrodoxin dependent glutamate synthase; and (6) gene MTCY31.20, encoding a putative cyclohexanone monooxygenase. Using gene specific primers in a second differential display PCR and by RT-PCR amplification, novel genes 1, 2, 3 and 4 were shown to be differentially up-regulated in the attenuated Mtb strain H37Ra compared to H37Rv and Erdman strain. Overall, we demonstrated that RAP-PCR, as a first step, is a quick and sensitive method for the identification and isolation of novel genes expressed in Mtb. Because of limitations inherent to the lack of specificity of arbitrary primers in the RAP-PCR method, a second differential display PCR and RT-PCR amplification with gene-specific primers was necessary in order to confirm differential expression of the identified genes.
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PMID:Identification of genes differentially expressed in Mycobacterium tuberculosis by differential display PCR. 989 69

Oxygen starvation triggers an adaptive stationary-phase response in Mycobacterium smegmatis. During this anaerobic stationary phase, RNA synthesis continues at a low but significant level. Employing a modified expressed-sequence-tag (EST) approach, in combination with the M. tuberculosis genome data and comparative Northern analysis, we have identified the first genes that show an increase in transcription in M. smegmatis cells that have entered anaerobic stationary phase. One gene encodes the counterpart of the M. tuberculosis NifS-like protein Rv1464. Two genes are homologues of M. tuberculosis Rv1460 and Rv3368c, of unknown function. Strikingly, several genes induced by oxygen starvation encode putative stress protection proteins (counterparts of M. tuberculosis DnaK, Rv0350; betaine-aldehyde dehydrogenase, Rv0768; thioredoxin reductase, Rv3913) and ABC transporters (counterparts of M. tuberculosis Rv1463, Rv1473, Rv3197). We conclude that development of general stress resistance and certain active transport processes might play a role in the survival of oxygen-starved M. smegmatis.
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PMID:Upregulation of stress response genes and ABC transporters in anaerobic stationary-phase Mycobacterium smegmatis. 1062 50


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