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Repetitive architecture of the Haemophilus influenzae Hia trimeric autotransporter.

Meng G, St Geme JW, Waksman G - J. Mol. Biol. (2008)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Institute of Structural and Molecular Biology at UCL/Birkbeck, London, UK.

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.

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Transmembrane structure of Hia973–1098. (a) Stereo ribbon diagram of the Hia973–1098 trimer. The three subunits are shown in magenta, yellow, and orange. (b) Stereo ribbon diagram of the HiaNeck domain. (c) Stereo ribbon diagram of the superimposed domains HiaNeck (blue), Neck in IN2 (red), and YadANeck (green) viewed from the side. (d) Stereo ribbon diagram of the same superimposed Neck domains viewed from the top. (e) Sequence alignment of the Neck domains between HiaNeck, Neck in IN2, and YadANeck.
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fig5: Transmembrane structure of Hia973–1098. (a) Stereo ribbon diagram of the Hia973–1098 trimer. The three subunits are shown in magenta, yellow, and orange. (b) Stereo ribbon diagram of the HiaNeck domain. (c) Stereo ribbon diagram of the superimposed domains HiaNeck (blue), Neck in IN2 (red), and YadANeck (green) viewed from the side. (d) Stereo ribbon diagram of the same superimposed Neck domains viewed from the top. (e) Sequence alignment of the Neck domains between HiaNeck, Neck in IN2, and YadANeck.

Mentions: Compared to the previously published Hia998–1098 structure, the structure of Hia973–1098 reveals the full extent of the helices passing through the β-barrel and an extra highly intertwined Neck domain (HiaNeck) sitting on top (Fig. 5a and b). Neck domains are short connector domains (∼ 20–30 residues; Fig. 5e) between α-helical coiled coils and β-regions18,20 that are often interrupted by the insertion of sequences to form IsNeck domains.19,21


Repetitive architecture of the Haemophilus influenzae Hia trimeric autotransporter.

Meng G, St Geme JW, Waksman G - J. Mol. Biol. (2008)

Transmembrane structure of Hia973–1098. (a) Stereo ribbon diagram of the Hia973–1098 trimer. The three subunits are shown in magenta, yellow, and orange. (b) Stereo ribbon diagram of the HiaNeck domain. (c) Stereo ribbon diagram of the superimposed domains HiaNeck (blue), Neck in IN2 (red), and YadANeck (green) viewed from the side. (d) Stereo ribbon diagram of the same superimposed Neck domains viewed from the top. (e) Sequence alignment of the Neck domains between HiaNeck, Neck in IN2, and YadANeck.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2597055&req=5

fig5: Transmembrane structure of Hia973–1098. (a) Stereo ribbon diagram of the Hia973–1098 trimer. The three subunits are shown in magenta, yellow, and orange. (b) Stereo ribbon diagram of the HiaNeck domain. (c) Stereo ribbon diagram of the superimposed domains HiaNeck (blue), Neck in IN2 (red), and YadANeck (green) viewed from the side. (d) Stereo ribbon diagram of the same superimposed Neck domains viewed from the top. (e) Sequence alignment of the Neck domains between HiaNeck, Neck in IN2, and YadANeck.
Mentions: Compared to the previously published Hia998–1098 structure, the structure of Hia973–1098 reveals the full extent of the helices passing through the β-barrel and an extra highly intertwined Neck domain (HiaNeck) sitting on top (Fig. 5a and b). Neck domains are short connector domains (∼ 20–30 residues; Fig. 5e) between α-helical coiled coils and β-regions18,20 that are often interrupted by the insertion of sequences to form IsNeck domains.19,21

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Institute of Structural and Molecular Biology at UCL/Birkbeck, London, UK.

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.

Show MeSH
Related in: MedlinePlus