2c7d: Difference between revisions

[[Image:2c7d.gif|left|200px]]<br /><applet load="2c7d" size="350" color="white" frame="true" align="right" spinBox="true"  

The double-ring chaperonin GroEL and its lid-like cochaperonin GroES form asymmetric complexes that, in the ATP-bound state, mediate productive folding in a hydrophilic, GroES-encapsulated chamber, the so-called cis cavity. Upon ATP hydrolysis within the cis ring, the asymmetric complex becomes able to accept non-native polypeptides and ATP in the open, trans ring. Here we have examined the structural basis for this allosteric switch in activity by cryo-EM and single-particle image processing. ATP hydrolysis does not change the conformation of the cis ring, but its effects are transmitted through an inter-ring contact and cause domain rotations in the mobile trans ring. These rigid-body movements in the trans ring lead to disruption of its intra-ring contacts, expansion of the entire ring and opening of both the nucleotide pocket and the substrate-binding domains, admitting ATP and new substrate protein.

2C7D is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2C7D OCA].  

[[Category: Clare, D K.]]

[[Category: Farr, G W.]]

[[Category: Horwich, A L.]]

[[Category: Ranson, N A.]]

[[Category: Saibil, H R.]]

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