2vbw
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Rv3291c gene from Mycobacterium tuberculosis codes for a transcriptional | + | Rv3291c gene from Mycobacterium tuberculosis codes for a transcriptional regulator belonging to the (leucine responsive regulatory protein/regulator of asparigine synthase C gene product) Lrp/AsnC-family. We have identified a novel effector-binding site from crystal structures of the apo protein, complexes with a variety of amino acid effectors, X-ray based ligand screening and qualitative fluorescence spectroscopy experiments. The new effector site is in addition to the structural characterization of another distinct site in the protein conserved in the related AsnC-family of regulators. The structures reveal that the ligand-binding loops of two crystallographically independent subunits adopt different conformations to generate two distinct effector-binding sites. A change in the conformation of the binding site loop 100-106 in the B subunit is apparently necessary for octameric association and also allows the loop to interact with a bound ligand in the newly identified effector-binding site. There are four sites of each kind in the octamer and the protein preferentially binds to aromatic amino acids. While amino acids like Phe, Tyr and Trp exhibit binding to only one site, His exhibits binding to both sites. Binding of Phe is accompanied by a conformational change of 3.7 A in the 75-83 loop, which is advantageously positioned to control formation of higher oligomers. Taken together, the present studies suggest an elegant control mechanism for global transcription regulation involving binding of ligands to the two sites, individually or collectively. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Mechanistic insights from the crystal structures of a feast/famine regulatory protein from Mycobacterium tuberculosis H37Rv., Shrivastava T, Ramachandran R, Nucleic Acids Res. 2007 Oct 25 | + | Mechanistic insights from the crystal structures of a feast/famine regulatory protein from Mycobacterium tuberculosis H37Rv., Shrivastava T, Ramachandran R, Nucleic Acids Res. 2007;35(21):7324-35. Epub 2007 Oct 25. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17962306 17962306] |
[[Category: Mycobacterium tuberculosis]] | [[Category: Mycobacterium tuberculosis]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: transcription regulator]] | [[Category: transcription regulator]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:55:04 2008'' |
Revision as of 16:55, 21 February 2008
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FEAST OR FAMINE REGULATORY PROTEIN (RV3291C)FROM M. TUBERCULOSIS COMPLEXED WITH L-PHENYLALANINE
Overview
Rv3291c gene from Mycobacterium tuberculosis codes for a transcriptional regulator belonging to the (leucine responsive regulatory protein/regulator of asparigine synthase C gene product) Lrp/AsnC-family. We have identified a novel effector-binding site from crystal structures of the apo protein, complexes with a variety of amino acid effectors, X-ray based ligand screening and qualitative fluorescence spectroscopy experiments. The new effector site is in addition to the structural characterization of another distinct site in the protein conserved in the related AsnC-family of regulators. The structures reveal that the ligand-binding loops of two crystallographically independent subunits adopt different conformations to generate two distinct effector-binding sites. A change in the conformation of the binding site loop 100-106 in the B subunit is apparently necessary for octameric association and also allows the loop to interact with a bound ligand in the newly identified effector-binding site. There are four sites of each kind in the octamer and the protein preferentially binds to aromatic amino acids. While amino acids like Phe, Tyr and Trp exhibit binding to only one site, His exhibits binding to both sites. Binding of Phe is accompanied by a conformational change of 3.7 A in the 75-83 loop, which is advantageously positioned to control formation of higher oligomers. Taken together, the present studies suggest an elegant control mechanism for global transcription regulation involving binding of ligands to the two sites, individually or collectively.
About this Structure
2VBW is a Single protein structure of sequence from Mycobacterium tuberculosis with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Mechanistic insights from the crystal structures of a feast/famine regulatory protein from Mycobacterium tuberculosis H37Rv., Shrivastava T, Ramachandran R, Nucleic Acids Res. 2007;35(21):7324-35. Epub 2007 Oct 25. PMID:17962306
Page seeded by OCA on Thu Feb 21 18:55:04 2008
