1rq7: Difference between revisions

[[Image:1rq7.gif|left|200px]]<br /><applet load="1rq7" size="350" color="white" frame="true" align="right" spinBox="true"  

We report three crystal structures of the Mycobacterium tuberculosis cell division protein FtsZ, as the citrate, GDP, and GTPgammaS complexes, determined at 1.89, 2.60, and 2.08A resolution. MtbFtsZ crystallized as a tight, laterally oriented dimer distinct from the longitudinal polymer observed for alphabeta-tubulin. Mutational data on Escherichia coli FtsZ suggest that this dimer interface is important for proper protofilament and "Z-ring" assembly and function. An alpha-to-beta secondary structure conformational switch at the dimer interface is spatially analogous to, and has many of the hallmarks of, the Switch I conformational changes exhibited by G-proteins upon activation. The presence of a gamma-phosphate in the FtsZ active site modulates the conformation of the "tubulin" loop T3 (spatially analogous to the G-protein Switch II); T3 switching upon gamma-phosphate ligation is directly coupled to the alpha-to-beta switch by steric overlap. The dual conformational switches observed here for the first time in an FtsZ link GTP binding and hydrolysis to FtsZ (and tubulin) lateral assembly and Z-ring contraction, and they are suggestive of an underappreciated functional analogy between FtsZ, tubulin and G-proteins.

1RQ7 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 <scene name='pdbligand=GDP:'>GDP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RQ7 OCA].  

[[Category: Borhani, D W.]]

[[Category: DeVito, J A.]]

[[Category: Leung, A K.W.]]

[[Category: Reynolds, R C.]]

[[Category: Ross, L J.]]

[[Category: White, E L.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:53:28 2008''