2GR8

Hia 1022-1098

Summary for 2GR8

• Entry DOI: 10.2210/pdb2gr8/pdb
• Related: 2GR7
• Descriptor: Adhesin (2 entities in total)
• Functional Keywords: trimeric autotransporter, adhesion, protein secretion, microbial pathogenesis, membrane protein
• Biological source: Haemophilus influenzae
• Total number of polymer chains: 6
• Total formula weight: 59045.78

Authors

Meng, G.,Waksman, G. (deposition date: 2006-04-23, release date: 2006-05-23, Last modification date: 2024-02-14)

Primary citation

Meng, G.,Surana, N.K.,St Geme III, J.W.,Waksman, G.
Structure of the outer membrane translocator domain of the Haemophilus influenzae Hia trimeric autotransporter.
Embo J., 25:2297-2304, 2006

PubMed Abstract: 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.

PubMed: 16688217
DOI: 10.1038/sj.emboj.7601132

Experimental method

X-RAY DIFFRACTION (2 Å)