Structure of the outer membrane translocator domain of the Haemophilus influenzae Hia trimeric autotransporter.

Journal Article (Journal Article)

Autotransporter proteins are defined by the ability to drive their own secretion across the bacterial outer membrane. The Hia autotransporter of Haemophilus influenzae belongs to the trimeric autotransporter subfamily and mediates bacterial adhesion to the respiratory epithelium. In this report, we present the crystal structure of the C-terminal end of Hia, corresponding to the entire Hia translocator domain and part of the passenger domain (residues 992-1098). This domain forms a beta-barrel with 12 transmembrane beta-strands, including four strands from each subunit. The beta-barrel has a central channel of 1.8 nm in diameter that is traversed by three N-terminal alpha-helices, one from each subunit. Mutagenesis studies demonstrate that the transmembrane portion of the three alpha-helices and the loop region between the alpha-helices and the neighboring beta-strands are essential for stability of the trimeric structure of the translocator domain, and that trimerization of the translocator domain is a prerequisite for translocator activity. Overall, this study provides important insights into the mechanism of translocation in trimeric autotransporters.

Full Text

Duke Authors

Cited Authors

  • Meng, G; Surana, NK; St Geme, JW; Waksman, G

Published Date

  • June 7, 2006

Published In

Volume / Issue

  • 25 / 11

Start / End Page

  • 2297 - 2304

PubMed ID

  • 16688217

Pubmed Central ID

  • PMC1478200

International Standard Serial Number (ISSN)

  • 0261-4189

Digital Object Identifier (DOI)

  • 10.1038/sj.emboj.7601132


  • eng

Conference Location

  • England