title: The 12-transmembrane helix transporters.
abstract: From the hydropathic profiles of their amino acid sequences many transport proteins are conceived to comprise 12-transmembrane alpha-helices. In only a few examples, however, is there genetical and/or biochemical evidence to support the 12-helix structure or illuminate the molecular mechanism of the transport process. A number of these transport proteins occur in evolutionarily related families, and sometimes superfamilies, indicating divergent evolution of the 12-helix structure. Other individual members or families of transport proteins are sufficiently different in amino acid sequence for their evolution to have taken place by convergence from independent ancestral origins.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Leeds, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Henderson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008566:Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D009626:Terminology as Topic
chemical_list: D002352:Carrier Proteins