Structure and function of complex I in animals and plants

a comparative view

authored by

Jennifer Senkler, Michael Senkler, Hans Peter Braun

Abstract

The mitochondrial NADH dehydrogenase complex (complex I) has a molecular mass of about 1000 kDa and includes 40–50 subunits in animals, fungi and plants. It is composed of a membrane arm and a peripheral arm and has a conserved L-like shape in all species investigated. However, in plants and possibly some protists it has a second peripheral domain which is attached to the membrane arm on its matrix exposed side at a central position. The extra domain includes proteins resembling prokaryotic gamma-type carbonic anhydrases. We here present a detailed comparison of complex I from mammals and flowering plants. Forty homologous subunits are present in complex I of both groups of species. In addition, five subunits are present in mammalian complex I, which are absent in plants, and eight to nine subunits are present in plant complex I which do not occur in mammals. Based on the atomic structure of mammalian complex I and biochemical insights into complex I architecture from plants we mapped the species-specific subunits. Interestingly, four of the five animal-specific and five of the eight to nine plant-specific subunits are localized at the inner surface of the membrane arm of complex I in close proximity. We propose that the inner surface of the membrane arm represents a workbench for attaching proteins to complex I, which are not directly related to respiratory electron transport, like nucleoside kinases, acyl-carrier proteins or carbonic anhydrases. We speculate that further enzyme activities might be bound to this micro-location in other groups of organisms.

Organisation(s)

Section Plant Molecular Biology and Plant Proteomics
Institute of Plant Genetics

Type

Review article

Journal

Physiologia plantarum

Volume

161

Pages

6-15

No. of pages

10

ISSN

0031-9317

Publication date

06.03.2017

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Physiology, Genetics, Plant Science, Cell Biology

Electronic version(s)

https://doi.org/10.15488/11654 (Access: Open)
https://doi.org/10.1111/ppl.12561 (Access: Closed)