The outer-membrane export signal of Porphyromonas gingivalis type IX secretion system (T9SS) is a conserved C-terminal β-sandwich domain

被引：50

作者：

de Diego, Inaki ^{[1
,11
]}

Ksiazek, Miroslaw ^{[2
,3
,4
]}

Mizgalska, Danuta ^{[2
]}

Koneru, Lahari ^{[4
]}

Golik, Przemyslaw ^{[2
]}

Szmigielski, Borys ^{[2
]}

Nowak, Magdalena ^{[2
]}

Nowakowska, Zuzanna ^{[2
]}

Potempa, Barbara ^{[4
]}

Houston, John A. ^{[4
]}

Enghild, Jan J. ^{[5
,6
]}

Thogersen, Ida B. ^{[5
,6
]}

Gao, Jinlong ^{[7
,8
,9
]}

Kwan, Ann H. ^{[10
]}

Trewhella, Jill ^{[10
]}

Dubin, Grzegorz ^{[2
,3
]}

Xavier Gomis-Rueth, F. ^{[1
]}

Ky-Anh Nguyen ^{[7
,8
,9
]}

Potempa, Jan ^{[2
,3
,4
]}

机构：

[1] CSIC, Dept Struct Biol, Maria de Maeztu Unit Excellence, Proteolysis Lab,Mol Biol Inst Barcelona, Barcelona Sci Pk, Barcelona, Spain

[2] Jagiellonian Univ, Dept Microbiol, Fac Biochem Biophys & Biotechnol, Krakow, Poland

[3] Jagiellonian Univ, Malopolska Ctr Biotechnol, Krakow, Poland

[4] Univ Louisville, Sch Dent, Dept Oral Immunol & Infect Dis, Louisville, KY 40292 USA

[5] Aarhus Univ, Dept Mol Biol & Genet, Aarhus, Denmark

[6] Aarhus Univ, Interdisciplinary Nanosci Ctr, Aarhus, Denmark

[7] Univ Sydney, Fac Dent, Sydney, NSW 2006, Australia

[8] Westmead Ctr Oral Hlth, Inst Dent Res, Sydney, NSW, Australia

[9] Westmead Inst Med Res, Sydney, NSW, Australia

[10] Univ Sydney, Fac Sci, Sydney, NSW 2006, Australia

[11] ALBA Synchrotron, Carretera BP1413 Km 3-3, Cerdanyola Del Valles, Spain

来源：

SCIENTIFIC REPORTS | 2016年 / 6卷

关键词：

TANNERELLA-FORSYTHIA; GLIDING MOTILITY; CRYSTAL-STRUCTURE; VIRULENCE FACTOR; MOLECULAR-CLONING; PROTEIN-STRUCTURE; GINGIPAIN; IDENTIFICATION; MECHANISM; RGPB;

D O I：

10.1038/srep23123

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

In the recently characterized Type IX Secretion System (T9SS), the conserved C-terminal domain (CTD) in secreted proteins functions as an outer membrane translocation signal for export of virulence factors to the cell surface in the Gram-negative Bacteroidetes phylum. In the periodontal pathogen Porphyromonas gingivalis, the CTD is cleaved off by PorU sortase in a sequence-independent manner, and anionic lipopolysaccharide (A-LPS) is attached to many translocated proteins, thus anchoring them to the bacterial surface. Here, we solved the atomic structure of the CTD of gingipain B (RgpB) from P. gingivalis, alone and together with a preceding immunoglobulin-superfamily domain (IgSF). The CTD was found to possess a typical Ig-like fold encompassing seven antiparallel beta-strands organized in two beta-sheets, packed into a beta-sandwich structure that can spontaneously dimerise through C-terminal strand swapping. Small angle X-ray scattering (SAXS) revealed no fixed orientation of the CTD with respect to the IgSF. By introducing insertion or substitution of residues within the inter-domain linker in the native protein, we were able to show that despite the region being unstructured, it nevertheless is resistant to general proteolysis. These data suggest structural motifs located in the two adjacent Ig-like domains dictate the processing of CTDs by the T9SS secretion pathway.

引用

页数：17

共 66 条

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