2EWW: Crystal Structure Of The Pilus Retraction Motor Pilt And Bound Atp

Citation:
Abstract
PilT is a hexameric ATPase required for bacterial type IV pilus retraction and surface motility. Crystal structures of ADP- and ATP-bound Aquifex aeolicus PilT at 2.8 and 3.2 A resolution show N-terminal PAS-like and C-terminal RecA-like ATPase domains followed by a set of short C-terminal helices. The hexamer is formed by extensive polar subunit interactions between the ATPase core of one monomer and the N-terminal domain of the next. An additional structure captures a nonsymmetric PilT hexamer in which approach of invariant arginines from two subunits to the bound nucleotide forms an enzymatically competent active site. A panel of pilT mutations highlights the importance of the arginines, the PAS-like domain, the polar subunit interface, and the C-terminal helices for retraction. We present a model for ATP binding leading to dramatic PilT domain motions, engagement of the arginine wire, and subunit communication in this hexameric motor. Our conclusions apply to the entire type II/IV secretion ATPase family.
PDB ID: 2EWWDownload
MMDB ID: 42703
PDB Deposition Date: 2005/11/7
Updated in MMDB: 2006/12
Experimental Method:
x-ray diffraction
Resolution: 3.2  Å
Source Organism:
Similar Structures:
Biological Unit for 2EWW: hexameric; determined by author
Molecular Components in 2EWW
Label Count Molecule
Proteins (6 molecules)
6
Twitching Motility Protein Pilt(Gene symbol: pilT)
Molecule annotation
Chemicals (6 molecules)
1
6
* Click molecule labels to explore molecular sequence information.

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