2FGK

Crystal structure of the ABC-cassette E631Q mutant of HlyB with bound ATP

Summary for 2FGK

• Entry DOI: 10.2210/pdb2fgk/pdb
• Related: 1MT0 1XEF 1ffa 1ffb 2FGJ
• Descriptor: Alpha-hemolysin translocation ATP-binding protein hlyB, ADENOSINE-5'-TRIPHOSPHATE (3 entities in total)
• Functional Keywords: abc-transporter, abc-cassette, atp-loaded dimer, transport protein
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane; Multi-pass membrane protein (Probable): P08716
• Total number of polymer chains: 4
• Total formula weight: 113036.18

Authors

Zaitseva, J.,Oswald, C.,Jumpertz, T.,Jenewein, S.,Holland, I.B.,Schmitt, L. (deposition date: 2005-12-22, release date: 2006-08-08, Last modification date: 2023-08-30)

Primary citation

Zaitseva, J.,Oswald, C.,Jumpertz, T.,Jenewein, S.,Wiedenmann, A.,Holland, I.B.,Schmitt, L.
A structural analysis of asymmetry required for catalytic activity of an ABC-ATPase domain dimer.
Embo J., 25:3432-3443, 2006

PubMed Abstract: The ATP-binding cassette (ABC)-transporter haemolysin (Hly)B, a central element of a Type I secretion machinery, acts in concert with two additional proteins in Escherichia coli to translocate the toxin HlyA directly from the cytoplasm to the exterior. The basic set of crystal structures necessary to describe the catalytic cycle of the isolated HlyB-NBD (nucleotide-binding domain) has now been completed. This allowed a detailed analysis with respect to hinge regions, functionally important key residues and potential energy storage devices that revealed many novel features. These include a structural asymmetry within the ATP dimer that was significantly enhanced in the presence of Mg2+, indicating a possible functional asymmetry in the form of one open and one closed phosphate exit tunnel. Guided by the structural analysis, we identified two amino acids, closing one tunnel by an apparent salt bridge. Mutation of these residues abolished ATP-dependent cooperativity of the NBDs. The implications of these new findings for the coupling of ATP binding and hydrolysis to functional activity are discussed.

PubMed: 16858415
DOI: 10.1038/sj.emboj.7601208

Experimental method

X-RAY DIFFRACTION (2.7 Å)