Format

Send to

Choose Destination
See comment in PubMed Commons below
EMBO J. 2002 Mar 1;21(5):942-53.

The Tim9p-Tim10p complex binds to the transmembrane domains of the ADP/ATP carrier.

Author information

1
Department of Chemistry and Biochemistry and the Molecular Biology Institute, Box 951569, UCLA, Los Angeles, CA 90095-1569, USA.

Abstract

The soluble Tim9p-Tim10p (Tim, translocase of inner membrane) complex of the mitochondrial intermembrane space mediates the import of the carrier proteins and is a component of the TIM22 import system. The mechanism by which the Tim9p-Tim10p complex assembles and binds the carriers is not well understood, but previous studies have proposed that the conserved cysteine residues in the 'twin CX3C' motif coordinate zinc and potentially generate a zinc-finger-like structure that binds to the matrix loops of the carrier proteins. Here we have purified the native and recombinant Tim9p-Tim10p complex, and show that both complexes resemble each other and consist of three Tim9p and three Tim10p. Results from inductively coupled plasma--mass spectrometry studies failed to detect zinc in the Tim9p-Tim10p complex. Instead, the cysteine residues seemingly formed disulfide linkages. The Tim9p-Tim10p complex bound specifically to the transmembrane domains of the ADP/ATP carrier, but had no affinity for Tim23p, an inner membrane protein that is inserted via the TIM22 complex. The chaperone-like Tim9p-Tim10p complex thus may prevent aggregation of the unfolded carrier proteins in the aqueous intermembrane space.

PMID:
11867522
PMCID:
PMC125908
DOI:
10.1093/emboj/21.5.942
[Indexed for MEDLINE]
Free PMC Article

Publication types, MeSH terms, Substances, Grant support

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 ...
    Support Center