2LQL

Solution structure of CHCH5

Summary for 2LQL

• Entry DOI: 10.2210/pdb2lql/pdb
• NMR Information: BMRB: 18318
• Descriptor: Coiled-coil-helix-coiled-coil-helix domain-containing protein 5 (1 entity in total)
• Functional Keywords: chch domain, mitochondrial import, mia40-dependent disulfide relay system, alpha-hairpin domain, protein binding
• Biological source: Homo sapiens (human)
• Total number of polymer chains: 1
• Total formula weight: 12691.36

Authors

Peruzzini, R.,Ciofi-Baffoni, S.,Banci, L.,Bertini, I. (deposition date: 2012-03-09, release date: 2012-10-24, Last modification date: 2024-11-20)

Primary citation

Banci, L.,Bertini, I.,Ciofi-Baffoni, S.,Jaiswal, D.,Neri, S.,Peruzzini, R.,Winkelmann, J.
Structural characterization of CHCHD5 and CHCHD7: Two atypical human twin CX(9)C proteins.
J.Struct.Biol., 180:190-200, 2012

PubMed Abstract: Twin CX(9)C proteins constitute a large protein family among all eukaryotes; are putative substrates of the mitochondrial Mia40-dependent import machinery; contain a coiled coil-helix-coiled coil-helix (CHCH) fold stabilized by two disulfide bonds as exemplified by three structures available for this family. However, they considerably differ at the primary sequence level and this prevents an accurate prediction of their structural models. With the aim of expanding structural information on CHCH proteins, here we structurally characterized human CHCHD5 and CHCHD7. While CHCHD5 has two weakly interacting CHCH domains which sample a range of limited conformations as a consequence of hydrophobic interactions, CHCHD7 has a third helix hydrophobically interacting with an extension of helix α2, which is part of the CHCH domain. Upon reduction of the disulfide bonds both proteins become unstructured exposing hydrophobic patches, with the result of protein aggregation/precipitation. These results suggest a model where the molecular interactions guiding the protein recognition between Mia40 and the disulfide-reduced CHCHD5 and CHCHD7 substrates occurs in vivo when the latter proteins are partially embedded in the protein import pore of the outer membrane of mitochondria.

PubMed: 22842048
DOI: 10.1016/j.jsb.2012.07.007

Experimental method

SOLUTION NMR