Journal of Structural and Functional Genomics

, 12:21

Crystal structure of secretory protein Hcp3 from Pseudomonas aeruginosa

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

Authors and Affiliations

  1. 1.Argonne National Laboratory, Biosciences Division, Midwest Center for Structural Genomics and Structural Biology CenterArgonneUSA
  2. 2.University of Toronto, Structural Genomics ConsortiumTorontoCanada
  3. 3.Clinical Genomics Centre/Proteomics, University Health NetworkTorontoCanada
  4. 4.Department of Biochemistry and Molecular BiologyUniversity of ChicagoChicagoUSA