title: Structural and functional probing of PorZ, an essential bacterial surface component of the type-IX secretion system of human oral-microbiomic Porphyromonas gingivalis.
abstract: Porphyromonas gingivalis is a member of the human oral microbiome abundant in dysbiosis and implicated in the pathogenesis of periodontal (gum) disease. It employs a newly described type-IX secretion system (T9SS) for secretion of virulence factors. Cargo proteins destined for secretion through T9SS carry a recognition signal in the conserved C-terminal domain (CTD), which is removed by sortase PorU during translocation. Here, we identified a novel component of T9SS, PorZ, which is essential for surface exposure of PorU and posttranslational modification of T9SS cargo proteins. These include maturation of enzyme precursors, CTD removal and attachment of anionic lipopolysaccharide for anchorage in the outer membrane. The crystal structure of PorZ revealed two β-propeller domains and a C-terminal β-sandwich domain, which conforms to the canonical CTD architecture. We further documented that PorZ is itself transported to the cell surface via T9SS as a full-length protein with its CTD intact, independently of the presence or activity of PorU. Taken together, our results shed light on the architecture and possible function of a novel component of the T9SS. Knowledge of how T9SS operates will contribute to our understanding of protein secretion as part of host-microbiome interactions by dysbiotic members of the human oral cavity.
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.|Department of Bacterial Genetics, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Lasica
authors.affiliation: Proteolysis Lab, Structural Biology Unit ("María-de-Maeztu¨ Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, Barcelona, Catalonia, Spain.
authors.forename: Theodoros
authors.initials: T
authors.lastname: Goulas
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Danuta
authors.initials: D
authors.lastname: Mizgalska
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Proteolysis Lab, Structural Biology Unit ("María-de-Maeztu¨ Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, Barcelona, Catalonia, Spain.
authors.forename: Iñaki
authors.initials: I
authors.lastname: de Diego
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Ksiazek
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Madej
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.|Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Proteolysis Lab, Structural Biology Unit ("María-de-Maeztu¨ Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, Barcelona, Catalonia, Spain.
authors.forename: Tibisay
authors.initials: T
authors.lastname: Guevara
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Nowak
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Potempa
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.|Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Apoorv
authors.initials: A
authors.lastname: Goel
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.
authors.forename: Maryta
authors.initials: M
authors.lastname: Sztukowska
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.|Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Apurva T
authors.initials: AT
authors.lastname: Prabhakar
authors.affiliation: Department of Cell Biochemistry, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Bzowska
authors.affiliation: Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Widziolek
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO), and the Department of Molecular Biology, Aarhus University, Århus, DK-8000, Denmark.
authors.forename: Ida B
authors.initials: IB
authors.lastname: Thøgersen
authors.affiliation: Interdisciplinary Nanoscience Center (iNANO), and the Department of Molecular Biology, Aarhus University, Århus, DK-8000, Denmark.
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Enghild
authors.affiliation: Institute of Dental Research, Westmead Centre for Oral Health and Westmead Institute for Medical Research, Sydney, NSW 2145, Australia.
authors.forename: Mary
authors.initials: M
authors.lastname: Simonian
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard University Medical School, Boston, MA, USA.
authors.forename: Arkadiusz W
authors.initials: AW
authors.lastname: Kulczyk
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, University of Sydney, Sydney, NSW 2006, Australia.|Institute of Dental Research, Westmead Centre for Oral Health and Westmead Institute for Medical Research, Sydney, NSW 2145, Australia.
authors.forename: Ky-Anh
authors.initials: KA
authors.lastname: Nguyen
authors.affiliation: Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.|Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland.|Małopolska Center of Biotechnology, Jagiellonian University, Krakow, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Potempa
authors.affiliation: Proteolysis Lab, Structural Biology Unit ("María-de-Maeztu¨ Unit of Excellence), Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, Barcelona, Catalonia, Spain.
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Gomis-Rüth
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D058947:Bacterial Secretion Systems; D002462:Cell Membrane / Q000378:metabolism; D018360:Crystallography, X-Ray; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D017353:Gene Deletion; D000080867:Gingipain Cysteine Endopeptidases; D006801:Humans; D064307:Microbiota; D009055:Mouth / Q000382:microbiology*; D010641:Phenotype; D010858:Pigmentation; D016966:Porphyromonas gingivalis / Q000378:metabolism*; D000072417:Protein Domains; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary; D000076342:Protein-Arginine Deiminases / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; D000080867:Gingipain Cysteine Endopeptidases; D003546:Cysteine Endopeptidases; D000076342:Protein-Arginine Deiminases