Journal of Structural and Functional Genomics

, 12:21

Crystal structure of secretory protein Hcp3 from Pseudomonas aeruginosa

Authors

  • Jerzy Osipiuk
    • Argonne National Laboratory, Biosciences Division, Midwest Center for Structural Genomics and Structural Biology Center
  • Xiaohui Xu
    • University of Toronto, Structural Genomics Consortium
  • Hong Cui
    • University of Toronto, Structural Genomics Consortium
  • Alexei Savchenko
    • University of Toronto, Structural Genomics Consortium
    • University of Toronto, Structural Genomics Consortium
    • Clinical Genomics Centre/Proteomics, University Health Network
    • Argonne National Laboratory, Biosciences Division, Midwest Center for Structural Genomics and Structural Biology Center
    • Department of Biochemistry and Molecular BiologyUniversity of Chicago
Article

DOI: 10.1007/s10969-011-9107-1

Cite this article as:
Osipiuk, J., Xu, X., Cui, H. et al. J Struct Funct Genomics (2011) 12: 21. doi:10.1007/s10969-011-9107-1

Abstract

The Type VI secretion pathway transports proteins across the cell envelope of Gram-negative bacteria. Pseudomonas aeruginosa, an opportunistic Gram-negative bacterial pathogen infecting humans, uses the type VI secretion pathway to export specific effector proteins crucial for its pathogenesis. The HSI-I virulence locus encodes for several proteins that has been proposed to participate in protein transport including the Hcp1 protein, which forms hexameric rings that assemble into nanotubes in vitro. Two Hcp1 paralogues have been identified in the P. aeruginosa genome, Hsp2 and Hcp3. Here, we present the structure of the Hcp3 protein from P. aeruginosa. The overall structure of the monomer resembles Hcp1 despite the lack of amino-acid sequence similarity between the two proteins. The monomers assemble into hexamers similar to Hcp1. However, instead of forming nanotubes in head-to-tail mode like Hcp1, Hcp3 stacks its rings in head-to-head mode forming double-ring structures.

Keywords

Type VI (T6SS) secretion systemHcp3Hcp1X-ray crystallographyStructural genomics

Abbreviations

T6SS

Type VI secretion system

Hcp1

Hemolysin-corregulated protein

PDB

Protein Data Bank

SeMet

Seleno-methionine

SAD

Single-wavelength anomalous diffraction

RMSD

Root mean square deviation

Copyright information

© Springer Science+Business Media B.V. (outside the USA)  2011