title: Converting bacteria to organelles: evolution of mitochondrial protein sorting.
abstract: During the evolution of mitochondria from free-living alpha-proteobacteria, many bacterial genes were transferred into the nuclear genome of eukaryotic cells. This required the development of both targeting signals on the respective polypeptides and protein translocation machineries (translocases) in the mitochondrial membranes. Most components of these translocases have no obvious homologies to bacterial proteins or proteins found in other organelles. Membrane integration of many inner membrane proteins, however, apparently occurs via a conserved sorting pathway whose components and characteristics resemble protein translocation in bacteria. Consistent with this, the topogenic signals of these mitochondrial inner membrane proteins mimic those of bacterial proteins. The requirement for post-translational transport to their final destination has placed considerable constraints on the evolution of mitochondrial protein sequences.
authors.affiliation: Institut für Physiologische Chemie, Universität München, Butenandtstrasse 5, 81377 Münich, Germany. Hannes.Hermann@bio.med.uni-muenchen.de
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Herrmann
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D008954:Models, Biological; D021381:Protein Transport / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins