Chaperonins assist protein folding with the consumption of ATP. They exist as multi-subunit protein assemblies comprising rings of subunits stacked back to back. In Escherichia coli, asymmetric intermediates of GroEL are formed with the co-chaperonin GroES and nucleotides bound only to one of the seven-subunit rings (the cis ring) and not to the opposing ring (the trans ring). The structure of the GroEL-GroES-(ADP)7 complex reveals how large en bloc movements of the cis ring's intermediate and apical domains enable bound GroES to stabilize a folding chamber with ADP confined to the cis ring. Elevation and twist of the apical domains double the volume of the central cavity and bury hydrophobic peptide-binding residues in the interface with GroES, as well as between GroEL subunits, leaving 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. When combined with new functional results, this negative allosteric mechanism suggests a model for an ATP-driven folding cycle that requires a double toroid.
==About this Structure==
==About this Structure==
1AON is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. The following page contains interesting information on the relation of 1AON with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb32_1.html Chaperones]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AON OCA].
1AON is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. The following page contains interesting information on the relation of 1AON with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb32_1.html Chaperones]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AON OCA].
==Reference==
The crystal structure of the asymmetric GroEL-GroES-(ADP)7 chaperonin complex., Xu Z, Horwich AL, Sigler PB, Nature. 1997 Aug 21;388(6644):741-50. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9285585 9285585]
[[Category: Chaperones]]
[[Category: Chaperones]]
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
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[[Category: Xu, Z.]]
[[Category: Xu, Z.]]
[[Category: Chaperonin assisted protein folding]]
[[Category: Chaperonin assisted protein folding]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 10:31:20 2008''
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Jun 26 17:03:29 2008''
1AON is a Protein complex structure of sequences from Escherichia coli. The following page contains interesting information on the relation of 1AON with [Chaperones]. Full crystallographic information is available from OCA.
