Crystal Structures of the Pilus Retraction Motor PilT Suggest Large Domain Movements and Subunit Cooperation Drive Motility

Kenneth A. Satyshur, Gregory A. Worzalla, Lorraine S. Meyer, Erin K. Heiniger, Kelly G. Aukema, Ana M. Misic, Katrina T. Forest

Research output: Contribution to journalArticlepeer-review

96 Scopus citations

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 Å 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.

Original languageEnglish (US)
Pages (from-to)363-376
Number of pages14
JournalStructure
Volume15
Issue number3
DOIs
StatePublished - Mar 2007

Bibliographical note

Funding Information:
We are grateful to Dr. James Keck for data collection on C2 crystals. We acknowledge the excellent technical assistance of APS staff at BioCARS (14 ID-B) and LS-CAT (32 ID-B) beamlines. This project was funded by the NIH (GM59721) and the W.M. Keck Foundation.

Keywords

  • CELLBIO
  • MICROBIO

Fingerprint Dive into the research topics of 'Crystal Structures of the Pilus Retraction Motor PilT Suggest Large Domain Movements and Subunit Cooperation Drive Motility'. Together they form a unique fingerprint.

Cite this