PDBsum entry 3emo

Membrane protein/cell adhesion

PDB id: 3emo

Contents

Protein chains

126 a.a. *

* Residue conservation analysis

PDB id:

3emo

Name:

Membrane protein/cell adhesion

Title:

Crystal structure of transmembrane hia 973-1098

Structure:

Hia (adhesin). Chain: c, a, b. Fragment: unp residues 937-1098. Engineered: yes

Source:

Haemophilus influenzae. Organism_taxid: 727. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

3.00Å R-factor: 0.221 R-free: 0.289

Authors:

G.Meng,G.Waksman

Key ref:

G.Meng et al. (2008). Repetitive architecture of the Haemophilus influenzae Hia trimeric autotransporter. J Mol Biol, 384, 824-836. PubMed id: 18948113 DOI: 10.1016/j.jmb.2008.09.085

Date:

24-Sep-08 Release date: 04-Nov-08

Protein chains

Q48152  (Q48152_HAEIF) -  Adhesin from Haemophilus influenzae

Seq: 1098 a.a.

Struc: 126 a.a.

DOI no: 10.1016/j.jmb.2008.09.085

J Mol Biol 384:824-836 (2008)

PubMed id: 18948113

Repetitive architecture of the Haemophilus influenzae Hia trimeric autotransporter.

G.Meng, J.W.St Geme, G.Waksman.

ABSTRACT

The Hia autotransporter of Haemophilus influenzae belongs to the trimeric autotransporter subfamily and mediates bacterial adherence to the respiratory epithelium. In this report, we show that the structure of Hia is characterized by a modular architecture containing repeats of structurally distinct domains. Comparison of the structures of HiaBD1 and HiaBD2 adhesive repeats and a nonadhesive repeat (a novel fold) shed light on the structural determinants of Hia adhesive function. Examination of the structure of an extended version of the Hia translocator domain revealed the structural transition between the C-terminal translocator domain and the N-terminal passenger domain, highlighting a highly intertwined domain that is ubiquitous among trimeric autotransporters. Overall, this study provides important insights into the mechanism of Hia adhesive activity and the overall structure of trimeric autotransporters.

Selected figure(s)

Figure 4.
Fig. 4. Structure comparison between Trp-ring domains. (a) Stereo ribbon diagram of the superimposed W1 (blue), W3 (green), and W5 (red) domains viewed from the side. (b) Stereo ribbon diagram of the superimposed Trp-ring domains viewed from the top. (c) Sequence alignment of the Trp-ring domains between Hia/Hsf/NhhA. In (a) and (b), the conserved residues at the trimeric interface are shown in stick representation. In (c), these residues are shown in blue.

Figure 6.
Fig. 6. Modular architecture of Hia and putative two-step adhesive mechanism. (a) Modular architecture of Hia adhesin. While the structures of IN1, W1, KG1, W3, IN2, W5, Neck, and transmembrane anchor/translocator domains are determined crystallographically, W2/W4 and KG2 are modeled based on W1/W3/W5 and KG1, respectively. Yellow rectangles represent the Hia sequences that are yet to be structurally characterized, including the predicted N-terminal GANG and C-terminal TTT domains. (b) A putative two-step adhesive mechanism utilized by Hia/Hsf-like adhesin to form an intimate association between the bacterium and the host cell. The adhesive Trp-ring domains with different binding capacities are shown in blue and red. The nonadhesive Trp-ring domains are shown in green.

The above figures are reprinted from an Open Access publication published by Elsevier: J Mol Biol (2008, 384, 824-836) copyright 2008.

Figures were selected by an automated process.