2bki: Difference between revisions

Here we solve a 2.4-A structure of a truncated version of the, reverse-direction myosin motor, myosin VI, that contains the motor domain, and binding sites for two calmodulin molecules. The structure reveals only, minor differences in the motor domain from that in plus-end directed, myosins, with the exception of two unique inserts. The first is near the, nucleotide-binding pocket and alters the rates of nucleotide association, and dissociation. The second unique insert forms an integral part of the, myosin VI converter domain along with a calmodulin bound to a novel target, motif within the insert. This serves to redirect the effective 'lever arm', of myosin VI, which includes a second calmodulin bound to an 'IQ motif', towards the pointed (minus) end of the actin filament. This repositioning, largely accounts for the reverse directionality of this class of myosin, motors. We propose a model incorporating a kinesin-like uncoupling/docking, mechanism to provide a full explanation of the movements of myosin VI.

2BKI is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus] and [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa] with SO4 and CA 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=2BKI OCA].  

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