Molecular insights into the mechanism of ATP-hydrolysis by the NBD of the ABC-transporter HlyB

FEBS Lett. 2006 Feb 13;580(4):1036-41. doi: 10.1016/j.febslet.2005.11.012. Epub 2005 Nov 21.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Dimerization
  • Hemolysin Proteins
  • Hydrolysis
  • Models, Molecular


  • Bacterial Proteins
  • Carrier Proteins
  • Hemolysin Proteins
  • Hlyb protein, Bacteria
  • Adenosine Triphosphate