Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it>
<p>Abstract</p> <p>Background</p> <p>Obg is a highly conserved GTP-binding protein that has homologues in bacteria, archaea and eukaryotes. In bacteria, Obg proteins are essential for growth, and they participate in spore formation, stress adaptation, ribosome assembly...
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| Format: | Article |
| Language: | English |
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BMC
2011-02-01
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| Series: | BMC Microbiology |
| Online Access: | http://www.biomedcentral.com/1471-2180/11/43 |
| _version_ | 1818916844665307136 |
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| author | Dhandayuthapani Subramanian Scofield Virginia L Saikolappan Sankaralingam Sasindran Smitha J |
| author_facet | Dhandayuthapani Subramanian Scofield Virginia L Saikolappan Sankaralingam Sasindran Smitha J |
| author_sort | Dhandayuthapani Subramanian |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Obg is a highly conserved GTP-binding protein that has homologues in bacteria, archaea and eukaryotes. In bacteria, Obg proteins are essential for growth, and they participate in spore formation, stress adaptation, ribosome assembly and chromosomal partitioning. This study was undertaken to investigate the biochemical and physiological characteristics of Obg in <it>Mycobacterium tuberculosis</it>, which causes tuberculosis in humans.</p> <p>Results</p> <p>We overexpressed <it>M. tuberculosis </it>Obg in <it>Escherichia coli </it>and then purified the protein. This protein binds to, hydrolyzes and is phosphorylated with GTP. An anti-Obg antiserum, raised against the purified Obg, detects a 55 kDa protein in immunoblots of <it>M. tuberculosis </it>extracts. Immunoblotting also discloses that cultured <it>M. tuberculosis </it>cells contain increased amounts of Obg in the late log phase and in the stationary phase. Obg is also associated with ribosomes in <it>M</it>. <it>tuberculosis</it>, and it is distributed to all three ribosomal fractions (30 S, 50 S and 70 S). Finally, yeast two-hybrid analysis reveals that Obg interacts with the stress protein UsfX, indicating that <it>M. tuberculosis </it>Obg, like other bacterial Obgs, is a stress related protein.</p> <p>Conclusions</p> <p>Although its GTP-hydrolyzing and phosphorylating activities resemble those of other bacterial Obg homologues, <it>M. tuberculosis </it>Obg differs from them in these respects: (a) preferential association with the bacterial membrane; (b) association with all three ribosomal subunits, and (c) binding to the stress protein UsfX, rather than to RelA. Generation of mutant alleles of Obg of <it>M. tuberculosis</it>, and their characterization in vivo, may provide additional insights regarding its role in this important human pathogen.</p> |
| first_indexed | 2024-12-20T00:24:38Z |
| format | Article |
| id | doaj.art-8cd15d73b2bf419581fdf67c2ee3f727 |
| institution | Directory Open Access Journal |
| issn | 1471-2180 |
| language | English |
| last_indexed | 2024-12-20T00:24:38Z |
| publishDate | 2011-02-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Microbiology |
| spelling | doaj.art-8cd15d73b2bf419581fdf67c2ee3f7272022-12-21T20:00:06ZengBMCBMC Microbiology1471-21802011-02-011114310.1186/1471-2180-11-43Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it>Dhandayuthapani SubramanianScofield Virginia LSaikolappan SankaralingamSasindran Smitha J<p>Abstract</p> <p>Background</p> <p>Obg is a highly conserved GTP-binding protein that has homologues in bacteria, archaea and eukaryotes. In bacteria, Obg proteins are essential for growth, and they participate in spore formation, stress adaptation, ribosome assembly and chromosomal partitioning. This study was undertaken to investigate the biochemical and physiological characteristics of Obg in <it>Mycobacterium tuberculosis</it>, which causes tuberculosis in humans.</p> <p>Results</p> <p>We overexpressed <it>M. tuberculosis </it>Obg in <it>Escherichia coli </it>and then purified the protein. This protein binds to, hydrolyzes and is phosphorylated with GTP. An anti-Obg antiserum, raised against the purified Obg, detects a 55 kDa protein in immunoblots of <it>M. tuberculosis </it>extracts. Immunoblotting also discloses that cultured <it>M. tuberculosis </it>cells contain increased amounts of Obg in the late log phase and in the stationary phase. Obg is also associated with ribosomes in <it>M</it>. <it>tuberculosis</it>, and it is distributed to all three ribosomal fractions (30 S, 50 S and 70 S). Finally, yeast two-hybrid analysis reveals that Obg interacts with the stress protein UsfX, indicating that <it>M. tuberculosis </it>Obg, like other bacterial Obgs, is a stress related protein.</p> <p>Conclusions</p> <p>Although its GTP-hydrolyzing and phosphorylating activities resemble those of other bacterial Obg homologues, <it>M. tuberculosis </it>Obg differs from them in these respects: (a) preferential association with the bacterial membrane; (b) association with all three ribosomal subunits, and (c) binding to the stress protein UsfX, rather than to RelA. Generation of mutant alleles of Obg of <it>M. tuberculosis</it>, and their characterization in vivo, may provide additional insights regarding its role in this important human pathogen.</p>http://www.biomedcentral.com/1471-2180/11/43 |
| spellingShingle | Dhandayuthapani Subramanian Scofield Virginia L Saikolappan Sankaralingam Sasindran Smitha J Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> BMC Microbiology |
| title | Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> |
| title_full | Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> |
| title_fullStr | Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> |
| title_full_unstemmed | Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> |
| title_short | Biochemical and physiological characterization of the GTP-binding protein Obg of <it>Mycobacterium tuberculosis</it> |
| title_sort | biochemical and physiological characterization of the gtp binding protein obg of it mycobacterium tuberculosis it |
| url | http://www.biomedcentral.com/1471-2180/11/43 |
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