Format

Send to:

Choose Destination
See comment in PubMed Commons below
EMBO J. 2012 Feb 1;31(3):731-40. doi: 10.1038/emboj.2011.468. Epub 2011 Dec 23.

Mechanism of nucleotide sensing in group II chaperonins.

Author information

  • 1Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.

Erratum in

  • EMBO J. 2012 Oct 3;31(19):3949-50.

Abstract

Group II chaperonins mediate protein folding in an ATP-dependent manner in eukaryotes and archaea. The binding of ATP and subsequent hydrolysis promotes the closure of the multi-subunit rings where protein folding occurs. The mechanism by which local changes in the nucleotide-binding site are communicated between individual subunits is unknown. The crystal structure of the archaeal chaperonin from Methanococcus maripaludis in several nucleotides bound states reveals the local conformational changes associated with ATP hydrolysis. Residue Lys-161, which is extremely conserved among group II chaperonins, forms interactions with the γ-phosphate of ATP but shows a different orientation in the presence of ADP. The loss of the ATP γ-phosphate interaction with Lys-161 in the ADP state promotes a significant rearrangement of a loop consisting of residues 160-169. We propose that Lys-161 functions as an ATP sensor and that 160-169 constitutes a nucleotide-sensing loop (NSL) that monitors the presence of the γ-phosphate. Functional analysis using NSL mutants shows a significant decrease in ATPase activity, suggesting that the NSL is involved in timing of the protein folding cycle.

PMID:
22193720
[PubMed - indexed for MEDLINE]
PMCID:
PMC3273386
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk