title: Convergence and divergence in the evolution of transport proteins.
abstract: Different families of transport proteins catalyze transmembrane solute translocation, employing different mechanisms and energy sources. Several of these functionally dissimilar proteins nevertheless exhibit similar structural units, consisting of six tightly packed alpha-helices which may comprise all or part of a transmembrane channel. It is now recognized that some of these families arose independently of each other by convergence, while others arose from common precursors by divergence. The former families apparently arose at different times in evolutionary history, in different groups of organisms, employing different routes.
authors.affiliation: Department of Biology, University of California at San Diego, La Jolla 92093-0116.
authors.forename: M H
authors.initials: MH
authors.lastname: Saier
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D005075:Biological Evolution; D002352:Carrier Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D007473:Ion Channels / Q000235:genetics / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological
chemical_list: D002352:Carrier Proteins; D007473:Ion Channels; D000251:Adenosine Triphosphatases