2v9p: Difference between revisions

Concerted, stochastic and sequential mechanisms of action have been, proposed for different hexameric AAA+ molecular motors. Here we report the, crystal structure of the E1 helicase from bovine papillomavirus, where, asymmetric assembly is for the first time observed in the absence of, nucleotide cofactors and DNA. Surprisingly, the ATP-binding sites adopt, specific conformations linked to positional changes in the DNA-binding, hairpins, which follow a wave-like trajectory, as observed previously in, the E1/DNA/ADP complex. The protein's assembly thus maintains such an, asymmetric state in the absence of DNA and nucleotide cofactors, allowing, consideration of the E1 helicase action as the propagation of a, conformational wave around the protein ring. The data imply that the, wave's propagation within the AAA+ domains is not necessarily coupled with, a strictly sequential hydrolysis of ATP. Since a single ATP hydrolysis, event would affect the whole hexamer, such events may simply serve to, rectify the direction of the wave's motion.

2V9P is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bovine_papillomavirus_type_2 Bovine papillomavirus type 2] with PO4 and MG as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2V9P OCA].  

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