title: Molecular insights into the mechanism of ATP-hydrolysis by the NBD of the ABC-transporter HlyB.
abstract: The ABC-transporter HlyB is a central element of the Type I protein secretion machinery, dedicated to export the E. coli toxin HlyA in a single step across the two membranes of the cell envelope. Here, we discuss recent insights into the structure and the mechanism of ATP-hydrolysis by the NBD of HlyB. Combining structural and biochemical data, we have suggested that substrate-assisted catalysis (SAC), but not general base catalysis, is responsible for ATP-hydrolysis in this NBD and might also operate in other NBDs. Finally, the implications and advantages of SAC are discussed in the context of ATP-induced dimerization of the NBDs.
authors.affiliation: Institute of Biochemistry, Heinrich Heine University Duesseldorf, Universitaetsstr. 1, 40225 Duesseldorf, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Hanekop
authors.forename: J
authors.initials: J
authors.lastname: Zaitseva
authors.forename: S
authors.initials: S
authors.lastname: Jenewein
authors.forename: I B
authors.initials: IB
authors.lastname: Holland
authors.forename: L
authors.initials: L
authors.lastname: Schmitt
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D019281:Dimerization; D006460:Hemolysin Proteins; D006868:Hydrolysis; D008958:Models, Molecular
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D006460:Hemolysin Proteins; C050837:Hlyb protein, Bacteria; D000255:Adenosine Triphosphate