SecA membrane cycling at SecYEG is driven by distinct ATP binding and hydrolysis events and is regulated by SecD and SecF.
The SecA subunit of E. coli preprotein translocase promotes protein secretion during cycles of membrane insertion and deinsertion at SecYEG. This process is regulated both by nucleotide binding and hydrolysis and by the SecD and SecF proteins. In the presence of associated preprotein, the energy of ATP binding at nucleotide-binding domain 1 (NBD1) drives membrane insertion of a 30 kDa domain of SecA, while deinsertion of SecA requires the hydrolysis of this ATP. SecD and SecF stabilize the inserted state of SecA. ATP binding at NBD2, though needed for preprotein translocation, is not needed for SecA insertion or deinsertion.
Dartmouth Medical School, Department of Biochemistry, Hanover, New Hampshire 03755-3844, USA.
A
A
Economou
J A
JA
Pogliano
J
J
Beckwith
D B
DB
Oliver
W
W
Wickner
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D001665:Binding Sites / Q000502:physiology; D001692:Biological Transport / Q000502:physiology; D004926:Escherichia coli / Q000737:chemistry* / Q000502:physiology; D029968:Escherichia coli Proteins; D006868:Hydrolysis; D008081:Liposomes / Q000378:metabolism; D008565:Membrane Proteins / Q000502:physiology; D026901:Membrane Transport Proteins; D009154:Mutation / Q000502:physiology; D011510:Proteolipids / Q000378:metabolism; D000069816:SEC Translocation Channels; D000081416:SecA Proteins
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008081:Liposomes; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011510:Proteolipids; D000069816:SEC Translocation Channels; C499394:SecD protein, E coli; C065493:SecE protein, E coli; C489583:SecF protein, E coli; C088616:SecG protein, E coli; C057841:SecY protein, E coli; C020485:proteoliposomes; C075767:secD protein, Bacteria; C075768:secF protein, Bacteria; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins