NDUFAF7 methylates arginine 85 in the NDUFS2 subunit of human complex I.

TitleNDUFAF7 methylates arginine 85 in the NDUFS2 subunit of human complex I.
Publication TypeJournal Article
Year of Publication2013
AuthorsRhein, VF, Carroll, J, Ding, S, Fearnley, IM, Walker, JE
JournalJ Biol Chem
Volume288
Issue46
Pagination33016-26
Date Published2013 Nov 15
ISSN1083-351X
KeywordsArginine, Cell Line, Tumor, Humans, Methylation, Methyltransferases, NADH Dehydrogenase, Protein Folding, Protein Structure, Secondary, Protein-Arginine N-Methyltransferases
Abstract

Complex I (NADH ubiquinone oxidoreductase) in mammalian mitochondria is an L-shaped assembly of 44 subunits. One arm is embedded in the inner membrane with the other protruding ∼100 Å into the matrix of the organelle. The extrinsic arm contains binding sites for NADH and the primary electron acceptor FMN, and it provides a scaffold for seven iron-sulfur clusters that form an electron pathway linking FMN to the terminal electron acceptor, ubiquinone, which is bound in the region of the junction between the arms. The membrane arm contains four antiporter-like domains, probably energetically coupled to the quinone site and involved in pumping protons from the matrix into the intermembrane space contributing to the proton motive force. Complex I is put together from preassembled subcomplexes. Their compositions have been characterized partially, and at least 12 extrinsic assembly factor proteins are required for the assembly of the complex. One such factor, NDUFAF7, is predicted to belong to the family of S-adenosylmethionine-dependent methyltransferases characterized by the presence in their structures of a seven-β-strand protein fold. In the present study, the presence of NDUFAF7 in the mitochondrial matrix has been confirmed, and it has been demonstrated that it is a protein methylase that symmetrically dimethylates the ω-N(G),N(G') atoms of residue Arg-85 in the NDUFS2 subunit of complex I. This methylation step occurs early in the assembly of complex I and probably stabilizes a 400-kDa subcomplex that forms the initial nucleus of the peripheral arm and its juncture with the membrane arm.

DOI10.1074/jbc.M113.518803
Alternate JournalJ. Biol. Chem.
Citation Key10.1074/jbc.M113.518803
PubMed ID24089531
PubMed Central IDPMC3829151
Grant ListMC_U105663148 / / Medical Research Council / United Kingdom
/ / Medical Research Council / United Kingdom