Intermolecular latency regulates the essential C-terminal signal peptidase and sortase of the Porphyromonas gingivalis type-IX secretion system.

Autor:	Mizgalska D; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Goulas T; Proteolysis Laboratory, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain.; Department of Food Science and Nutrition, School of Agricultural Sciences, University of Thessaly, 43100 Karditsa, Greece., Rodríguez-Banqueri A; Proteolysis Laboratory, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain., Veillard F; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Madej M; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Małecka E; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Szczesniak K; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Ksiazek M; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland., Widziołek M; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland.; Department of Evolutionary Immunology, Institute of Zoology and Biomedical Research, Faculty of Biology, Jagiellonian University, 30-387 Kraków, Poland., Guevara T; Proteolysis Laboratory, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain., Eckhard U; Proteolysis Laboratory, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain., Solà M; Structural MitoLab, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain; xgrcri@ibmb.csic.es maria.sola@ibmb.csic.es jan.potempa@icloud.com., Potempa J; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland; xgrcri@ibmb.csic.es maria.sola@ibmb.csic.es jan.potempa@icloud.com.; Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY 40202., Gomis-Rüth FX; Proteolysis Laboratory, Department of Structural Biology, Higher Scientific Research Council (CSIC), Molecular Biology Institute of Barcelona, 08028 Barcelona, Catalonia, Spain; xgrcri@ibmb.csic.es maria.sola@ibmb.csic.es jan.potempa@icloud.com.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Oct 05; Vol. 118 (40). Date of Electronic Publication: 2021 Sep 30.
DOI:	10.1073/pnas.2103573118
Abstrakt:	Porphyromonas gingivalis is a keystone pathogen of the human dysbiotic oral microbiome that causes severe periodontitis. It employs a type-IX secretion system (T9SS) to shuttle proteins across the outer membrane (OM) for virulence. Uniquely, T9SS cargoes carry a C-terminal domain (CTD) as a secretion signal, which is cleaved and replaced with anionic lipopolysaccharide by transpeptidation for extracellular anchorage to the OM. Both reactions are carried out by PorU, the only known dual-function, C-terminal signal peptidase and sortase. PorU is itself secreted by the T9SS, but its CTD is not removed; instead, intact PorU combines with PorQ, PorV, and PorZ in the OM-inserted "attachment complex." Herein, we revealed that PorU transits between active monomers and latent dimers and solved the crystal structure of the ∼260-kDa dimer. PorU has an elongated shape ∼130 Å in length and consists of seven domains. The first three form an intertwined N-terminal cluster likely engaged in substrate binding. They are followed by a gingipain-type catalytic domain (CD), two immunoglobulin-like domains (IGL), and the CTD. In the first IGL, a long "latency β-hairpin" protrudes ∼30 Å from the surface to form an intermolecular β-barrel with β-strands from the symmetric CD, which is in a latent conformation. Homology modeling of the competent CD followed by in vivo validation through a cohort of mutant strains revealed that PorU is transported and functions as a monomer through a C 690 /H 657 catalytic dyad. Thus, dimerization is an intermolecular mechanism for PorU regulation to prevent untimely activity until joining the attachment complex. Competing Interests: The authors declare no competing interest.
Databáze:	MEDLINE
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