title: The transmembrane helices of the L, M, and N subunits of Complex I from E. coli can be assigned on the basis of conservation and hydrophobic moment analysis.
abstract: An assignment of the transmembrane helices of subunits L, M, and N of the Escherichia coli Complex I has been made from the helices as determined in a recent crystal structure [Efromov et al., Nature (2010) 465, 441-446]. The amino acid sequences of the three subunits were evaluated for hydrophobicity, and hydrophobic moments, to identify the helices that are likely to be in contact with membrane lipids. Using 29 closely related species, a similar analysis of average conservation, and conservation moments was performed. In each subunit, transmembrane helices 9 and 12 are predicted to form the discontinuous helices, which are likely to play a key role in function.
authors.affiliation: Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA. svik@smu.edu
authors.forename: Steven B
authors.initials: SB
authors.lastname: Vik
mesh_terms: D000595:Amino Acid Sequence; D042967:Electron Transport Complex I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D021122:Protein Subunits; D042967:Electron Transport Complex I