Motion in GroEL [groel]

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Classification Complex Motion [C----]

Structures 1AON Conformation 1 [ PartsList ] 1DER Conformation 2 [ PartsList ] 1GRL Conformation 3 [ PartsList ] 1OEL Conformation 4 [ PartsList ]

Description Chaperonins enhance protein folding with the consumption of ATP. They exist as multi-subunit protein assemblies comprising rings of subunits stacked back to back. The recent crystallographic structure of GroEL-GroES-(ADP)7. (Xu et al., 1997) show that both subunit and domain motions are involved in the operation of the GroEl chaperone. The cis ring intermediate and apical domains engage in large enbloc movements and thereby enable bound GroES to stabilize a folding chamber with ADP confined to the cis ring. The apical domains twist and elevate, doubling the volume of the central cavity and burying hydrophobic residues in the interface with GroES, as well as between GroEL subunits. This leaves a hydrophilic cavity lining that is conducive to protein folding. An inward tilt of the cis equatorial domain causes an outward tilt in the trans ring that opposes the binding of a second GroES. In marked contrast to the unaffected trans GroEL subunit, the structure of the bound cis GroEL subunit shows profound differences, which Xu et al. attribute to dramatic domain rearrangements involving both the intermediate and apical domains. The intermediate domain swings down towards the equatorial domain and the central channel, pivoting approximately 25 degrees around Pro 137 and Gly410, which form a slender link to the equatorial domain. The movement closes the nucleotide-binding site that is located on the top inner surface of the equatorial domain, both within the same subunit and with a neighboring subunit. Their interactions seem sterically to impede the dissociation of ADP from the cis ring, and they structurally relate GroES binding to the presence of ATP and to ATP hydrolysis in the cis ring. Second, the apical domain swings up 60 degrees relative to the equator and twists around the long axis of the domain by about 90 degrees, leading to an interaction with mobile loop of GroES. The pivot point of the apical movement is again a slender link, in this case a pair of Gly residues (Gly 192 and Gly 375) between the intermediate and apical domains, which links the position of the apical domain to the nucleotide-induced/stabilized movement of the intermediate domain. The movement of the hinge in response to nucleotide directly couples the binding of GroES to the presence of the nucleotide, and vice versa. Both domain movements (intermediate and apical) are largely en bloc, with RMS deviations for superposition of these domains upon their unliganded counterparts of 0.91 and 1.66 A for the intermediate and apical domains, respectively. These domain movements, especially in the apical domains, dramatically rearrange the cavity formed by the cis GroEL ring and GroES. The volume of the cavity is doubled, and the polypeptide binding properties of the cavity lining are changed.

Particular values describing motion Creation Date = 19971130 Experimental Methods = x (Traditional x-ray) Location of a Hinge (residue selection) = 137 Location of a Hinge (residue selection) = 192 Location of a Hinge (residue selection) = 375 Location of a Hinge (residue selection) = 410 Modification Date = 1999-05-24 16:38:41.000

References K Braig, Z Otwinowski, R Hegde, D C Boisvert, A Joachimiak, A L Horwich and P B Sigler (1994). The crystal structure of the bacterial chaperonin GroEL at 2.8 A [see comments]. Nature. 371: 578-586. [Medline info for 95021709] Rye HS, Burston SG, Fenton WA, Beechem JM, Xu Z, Sigler PB, Horwich AL (1997). Distinct actions of cis and trans ATP within the double ring of the chaperonin GroEL. Nature 388(6644):792-798. [Medline info for 97429955] Xu Z, Horwich AL, Sigler PB (1997). The crystal structure of the asymmetric GroEL-GroES-(ADP)7 chaperonin complex. Nature 388(6644):741-750. [Medline info for 97429947]

Data and Graphics Custom movies Morph of entire double ring of GroEL (1AON->1DER). Several movies and structure files available.

GO terms associated with structures Molecular function protein binding, ATP binding Biological process cellular protein metabolism, protein folding

Morphs

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Best representative Morph Morph name Structure #1 Structure #2 Residues [ ] [ ]

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Copyright 1995-2005 M. Gerstein, W. Krebs, S. Flores, N. Echols, and others
Email: Mark.Gerstein _at_ yale.edu