Essential regions in the membrane domain of bacterial complex I (NDH-1): the machinery for proton translocation.

Abstract

The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) is the first and largest enzyme of the respiratory chain which has a central role in cellular energy production and is implicated in many human neurodegenerative diseases and aging. It is believed that the peripheral domain of complex I/NDH-1 transfers the electron from NADH to Quinone (Q) and the redox energy couples the proton translocation in the membrane domain. To investigate the mechanism of the proton translocation, in a series of works we have systematically studied all membrane subunits in the Escherichia coli NDH-1 by site-directed mutagenesis. In this mini-review, we have summarized our strategy and results of the mutagenesis by depicting residues essential for proton translocation, along with those for subunit connection. It is suggested that clues to understanding the driving forces of proton translocation lie in the similarities and differences of the membrane subunits, highlighting the communication of essential charged residues among the subunits. A possible proton translocation mechanism with all membrane subunits operating in unison is described.

• Authors: Motoaki Sato, Jesus Torres-Bacete, Prem Kumar Sinha, Akemi Matsuno-Yagi, Takao Yagi
• Journal: Journal of bioenergetics and biomembranes (J Bioenerg Biomembr) Vol. 46 Issue 4 Pg. 279-87 (Aug 2014) ISSN: 1573-6881 [Electronic] United States
• PMID: 24973951 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Review)

Chemical References

• Benzoquinones
• Escherichia coli Proteins
• Membrane Proteins
• NuoH protein, E coli
• Protein Subunits
• Protons
• NAD
• quinone
• Electron Transport Complex I

Topics

• Benzoquinones (chemistry, metabolism)
• Cell Membrane (chemistry, genetics, metabolism)
• Electron Transport Complex I (chemistry, genetics, metabolism)
• Escherichia coli (chemistry, genetics, metabolism)
• Escherichia coli Proteins (chemistry, genetics, metabolism)
• Humans
• Ion Transport (physiology)
• Membrane Proteins (chemistry, genetics, metabolism)
• Mutagenesis, Site-Directed
• NAD (chemistry, genetics, metabolism)
• Protein Structure, Tertiary
• Protein Subunits (chemistry, genetics, metabolism)
• Protons