title: Structure and function of SecA, the preprotein translocase nanomotor.
abstract: Most secretory proteins that are destined for the periplasm or the outer membrane are exported through the bacterial plasma membrane by the Sec translocase. Translocase is a complex nanomachine that moves processively along its aminoacyl polymeric substrates effectively pumping them to the periplasmic space. The salient features of this process are: (a) a membrane-embedded "clamp" formed by the trimeric SecYEG protein, (b) a "motor" provided by the dimeric SecA ATPase, (c) regulatory subunits that optimize catalysis and (d) both chemical and electrochemical metabolic energy. Significant recent strides have allowed structural, biochemical and biophysical dissection of the export reaction. A model incorporating stepwise strokes of the translocase nanomachine at work is discussed.
authors.affiliation: Laboratory Unicellular, Organisms Group, Institute of Molecular Biology and Biotechnology, FO.R.T.H. and Department of Biology, University of Crete, Vassilika Vouton, P.O. Box 1527, GR-711 10 Iraklio, Crete, Greece.
authors.forename: Eleftheria
authors.initials: E
authors.lastname: Vrontou
authors.forename: Anastassios
authors.initials: A
authors.lastname: Economou
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000502:physiology*; D011487:Protein Conformation; D021381:Protein Transport / Q000502:physiology; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins