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)

A suppressor-containing strain of Mycobacterium smegmatis SN2 was isolated by transferring an amber suppressor carried on the plasmid of Pseudomonas pseudoalcaligenes ERA through transformation. Amber mutants of mycobacteriophage I3 were isolated.
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PMID:Interfamilial transfer of amber suppressor gene for the isolation of amber mutants of Mycobacteriophage I3. 44 92

Ribosomal RNA (rRNA) from a fast growing nonpathogenic strain of mycobacteria, Mycobacterium smegmatis SN2, was analyzed for the presence of minor nucleotides. Of the sixteen modified nucleotides detected, the identity of twelve has been established and their molar ratios were determined. These nucleotides include m1A, m2A, m6A, m6(2)A, m7G, m5C, rT, CmpC, CmpG, GmpG, UmpG and UmpU. The distinct features of the mycobacterial rRNA modifications include: (i) relatively substantial level of methylation, a feature distinct from that of the tRNA species which are unique in being under methylated in these bacteria, (ii) N1 methyl adenine representing the bulk of the modified bases, (iii) the lack of ribose methylation on any two successive nucleotides, and (iv) the presence of N6,N6-dimethyl adenosines, which are the target sites of the antibiotic kasugamycin, although the bacterial growth is insensitive to the drug.
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PMID:Ribosomal RNA methylation in Mycobacterium smegmatis SN2. 344 25

Arginyl-tRNA synthetase [L-Arg: tRNAArg ligase (AMP forming) EC 6.1.1.19] has been purified to homogeneity from Mycobacterium smegmatis SN2. The enzyme is a monomer of molecular weight 56,000. The kinetic patterns obtained by initial velocity and product inhibition studies are consistent with a rapid equilibrium random ter ter mechanism. Polyamines stimulated the formation of arginyl-tRNA, the stimulation being more significant at sub-optimal Mg2+ concentrations. Initial velocity studies performed in the presence of sub-optimal Mg2+ and spermine also indicated that the kinetic mechanism remained sequential random. Various attempts to reveal the formation of enzyme-bound arginyl-adenylate provided no evidence for its existence. The reverse reaction, i.e., the deacylation of arginyl-tRNA, required both AMP and PPi. This observation is consistent with the mechanism proposed.
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PMID:Arginyl-tRNA synthetase from Mycobacterium smegmatis SN2: purification and kinetic mechanism. 378 54

Lysyl-tRNA synthetase [L-lys:tRNAlys ligase (AMP forming) EC:6.1.1.6] has been purified to homogeneity from Mycobacterium smegmatis SN2. The enzyme is a dimer of molecular weight 126,000 and is composed of identical subunits. A detailed analysis of the kinetic mechanism of the lysyl-tRNA synthetase has been carried out. A rapid equilibrium random ter ter mechanism is proposed based on initial velocity and product inhibition studies. There is no evidence for the formation of enzyme-bound lysyl-adenylate. The reverse reaction, studied by the deacylation of lysyl-tRNA, requires the presence of both AMP and PPi. This observation is consistent with the mechanism proposed.
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PMID:Purification and kinetic mechanism of lysyl-tRNA synthetase from Mycobacterium smegmatis SN2. 385 66

Transduction of resistance to isoniazid and streptomycin as well as susceptibility to isoniazid in Mycobacterium smegmatis SN2 has been demonstrated. A method has been described for the selection of isoniazid-susceptible variants after transduction of susceptibility.
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PMID:Transduction of isoniazid susceptibility-resistance and streptomycin resistance in mycobacteria. 479 84

Electron micrographs of the transducing phage I3 for Mycobacterium smegmatis strain SN2 revealed a phage with a contractile tail and a head with isometric symmetry and visible capsomeres.
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PMID:Structure of a transducing mycobacteriophage. 501 33

Mycobacterium smegmatis SN2 does not exhibit natural competence for the uptake of phage I3 DNA. Competence can artificially be induced by treatment with glycine or CaCl2, and the combination of both is even more effective. The efficiency of transfection can be improved by inclusion of protamine sulphate and heterologous RNA in the system. From 32P DNA uptake studies the major barrier for the entry of DNA has been found to be the complex cell wall. The efficiency of transfection calculated on the basis of fraction of DNA which has entered the cell is comparable to that of other bacterial systems. The phage development takes a longer time (7 h for one cycle) after transfection, as compared to infection (4 h).
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PMID:Transfection of Mycobacterium smegmatis SN2 with mycobacteriophage I3 DNA. 666 87

Deoxyribonucleic acid modification in six strains of mycobacteria was investigated. The presence of 5-methylcytosine in the virulent strain Mycobacterium tuberculosis H37Rv and its absence in the avirulent strain M. tuberculosis H37Ra and other saprophytic, fast-growing mycobacteria appear to be the salient features. However, deoxyribonucleic acid from M. smegmatis SN2 lysogenized with the temperature phage I3 showed the presence of 5-methylcytosine. All of the strains had N6-methyladenine.
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PMID:Deoxyribonucleic acid methylation in mycobacteria. 679 84

The ftsH gene of Mycobacterium smegmatis SN2 (MsftsH) was cloned from two independent partial genomic DNA libraries and characterized, along with the identification of ephA and folE as the neighbouring upstream and downstream genes respectively. The genomic organization of the MsftsH locus was found to be identical to that of the Mycobacterium tuberculosis ftsH gene (MtftsH) and similar to that of other bacterial genera, but with divergence in the upstream region. The MsftsH gene is 2.3 kb in size and encodes the AAA (ATPases Associated with diverse cellular Activities) family Zn(2+)-metalloprotease FtsH (MsFtsH) of 85 kDa molecular mass. This was demonstrated from the expression of the full-length recombinant gene in Escherichia coli JM109 cells and from the identification of native MsFtsH in M. smegmatis SN2 cell lysates by Western blotting with anti-MtFtsH and anti-EcFtsH antibodies respectively. The recombinant and the native MsFtsH proteins were found localized to the membrane of E. coli and M. smegmatis cells respectively. Expression of MsFtsH protein in E. coli was toxic and resulted in growth arrest and filamentation of cells. The MsftsH gene did not complement lethality of a DeltaftsH3 : : kan mutation in E. coli, but when expressed in E. coli cells, it efficiently degraded conventional FtsH substrates, namely sigma(32) protein and the protein translocase subunit SecY, of E. coli cells.
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PMID:Genomic organization and in vivo characterization of proteolytic activity of FtsH of Mycobacterium smegmatis SN2. 1528 59

Haloalkane dehalogenases are enzymes well known to be important in bioremediation; the organisms from which they are produced are able to clean up toxic organohalides from polluted environments. However, besides being found in such contaminated environments, these enzymes have also been found in root or tissue-colonizing bacterial species. The haloalkane dehalogenase Rv2579 from Mycobacterium tuberculosis H37Rv has been cloned, expressed, purified and its crystal structure determined at high resolution (1.2A). In addition, the crystal structure of the enzyme has been determined in complex with the product from the reaction with 1,3-dibromopropane, i.e. 1,3-propanediol and in complex with the classical substrate of haloalkane dehalogenases, 1,2-dichloroethane. The enzyme is a two-domain protein having a catalytic domain of an alpha/beta hydrolase fold and a cap domain. The active site residues and the halide-stabilizing residues have been identified as Asp109, Glu133, His273, Asn39 and Trp110. Its overall structure is similar to those of other known haloalkane dehalogenases. Its mechanism of action involves an SN2 nucleophilic displacement.
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PMID:X-ray crystal structure of Mycobacterium tuberculosis haloalkane dehalogenase Rv2579. 1806 34


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