View source for 2vbx

[[Image:2vbx.jpg|left|200px]]<br /><applet load="2vbx" size="450" color="white" frame="true" align="right" spinBox="true" 
caption="2vbx, resolution 2.75&Aring;" />
'''FEAST OR FAMINE REGULATORY PROTEIN (RV3291C)FROM M. TUBERCULOSIS COMPLEXED WITH L-PHENYLALANINE'''<br />

==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==
2VBX is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis] with HIS as [http://en.wikipedia.org/wiki/ligand ligand]. Known structural/functional Sites: <scene name='pdbsite=AC1:HIS Binding Site For Chain A'>AC1</scene> and <scene name='pdbsite=AC2:HIS Binding Site For Chain A'>AC2</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2VBX 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 Oct 25;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17962306 17962306]
[[Category: Mycobacterium tuberculosis]]
[[Category: Single protein]]
[[Category: Ramachandran, R.]]
[[Category: Shrivastava, T.]]
[[Category: HIS]]
[[Category: dna-binding]]
[[Category: dna-binding protein]]
[[Category: feast/famine regulatory protein]]
[[Category: histidine complex]]
[[Category: lrp]]
[[Category: m. tuberculosis]]
[[Category: rv3291c]]
[[Category: transcription]]
[[Category: transcription regulation]]
[[Category: transcription regulator]]

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 20:34:50 2007''