细菌分泌系统研究进展
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摘要
<正>细菌在长期的进化过程中不断和宿主发生互作,通过自身分泌的蛋白作用于特定的宿主细胞引起特异性或非特异性的免疫应答。细菌所分泌的蛋白在营养获得、适应环境、种内和种间信号通迅以及毒力方面起着至关重要的作用。在革兰阴性菌中,分泌的蛋白必须穿过两个膜:细胞
引文
[1]Dautin N,Bernstein H D.Protein secretion in gram-negative bacteria via the autotransporter pathway[J].Annu Rev Microbiol,2007,61(1):89-112.
[2]Abdallah A M,van Pittius N C,Champion P A,et al.Type VIIsecretion-Mycobacteria show the way[J].Nat Rev Microbiol,2007,5(11):883-891.
[3]Goebel W,Hedgpeth J.Cloning and functional characterization of the plasmid-encoded hemolysin determinant of Escherichia coli[J].J Bacteriol,1982,151(3):1290-1298.
[4]Morgan J L W,Acheson J F,Zimmer J.Structure of a Type-1secretion system ABC transporter[J].Structure,2017,25(3):522-529.
[5]Thomas S,Holland I B,Schmitt L.The Type 1 secretion pathway-The hemolysin system and beyond[J].Biochim Biophys Acta,2014,1843(8):1629-1641.
[6]Gerlach R G,J覿ckel D,Stecher B,et al.Salmonella pathogenicity island 4 encodes a giant non-fimbrial adhesin and the cognate type 1 secretion system[J].Cell Microbiol,2007,9(7):1834-1850.
[7]Yoshida K,Toyofuku M,Obana N,et al.Biofilm formation by Paracoccus denitrificans requires a type I secretion system-dependent adhesin Bap A[J].FEMS Microbiol Lett,2017,364(4),doi:10.1093.
[8]Harding C M,Pulido M R,Di V G,et al.Pathogenic acinetobacter species have a functional Type I secretion system and contact-dependent inhibition systems[J].J Bio Chem,2017,292(22):9075-9087.
[9]Lesic B,Starkey M,He J,et al.Quorum sensing differentially regulates Pseudomonas aeruginosa type VI secretion locus I and homologous loci II and III,which are required for pathogenesis[J].Microbiology,2009,155(9):2845-2855.
[10]Ferrandez Y,Condemine G.Novel mechanism of outer membrane targeting of proteins in Gram-negative bacteria[J].Mol Microbiol,2008,69(6):1349-1357.
[11]Pugsley A P.The complete general secretory pathway in gramnegative bacteria[J].Microbiol Rev,1993,57(1):50-108.
[12]Voulhoux R,Ball G,Ize B,et al.Involvement of the twin-arginine translocation system in protein secretion via the type IIpathway[J].EMBO J,2001,20(23):6735-6741.
[13]Pugsley A P,Possot O S N,Hardie K R,et al.Recent progress and future directions in studies of the main terminal branch of the general secretory pathway in gram-negative bacteria-a review[J].Gene,1997,192(1):13-19.
[14]Lory S.Secretion of proteins and assembly of bacterial surface organelles:Shared pathways of extracellular protein targeting[J].Curr Opin Microbiol,1998,1(1):27-35.
[15]Francetic O,Belin D,Badaut C,et al.Expression of the endogenous type II secretion pathway in Escherichia coli leads to chitinase secretion[J].EMBO J,2000,19(24):6697-6703.
[16]Corbett M,Virtue S,Bell K,et al.Identification of a new quorum-sensing-controlled virulence factor in Erwinia carotovora subsp.atroseptica secreted via the type II targeting pathway[J].Mol Plant Microbe Interact,2005,18(4):334-342.
[17]Ray S K,Rajeshwari R,Sonti R V.Mutants of Xanthomonas oryzae pv.oryzae deficient in general secretory pathway are virulence deficient and unable to secrete xylanase[J].Mol Plant Microbe Interact,2000,13(4):394-401.
[18]Kubori T,Matsushima Y,Dai N,et al.Supramolecular structure of the Salmonella typhimurium Type III protein secretion system[J].Science,1998,280(5363):602-605.
[19]Coburn B,Sekirov I,Finlay B B.Type III secretion systems and disease[J].Clin Microbiol Rev,2007,20(4):535-549.
[20]Van Gijsegem F,Gough C,Zischek C,et al.The hrp gene locus of Pseudomonas solanacearum,which controls the production of a type III secretion system,encodes eight proteins related to components of the bacterial flagellar biogenesis complex[J].Mol Microbiol,1995,15(6):1095-1114.
[21]Gaytán M O,Martínez-Santos V I,Soto E,et al.Type three secretion system in attaching and effacing pathogens[J].Front Cell Infect Microbiol,2016,6(21):129.
[22]Bliska J B,Wang X,Viboud G I,et al.Modulation of innate immune responses by Yersinia type III secretion system translocators and effectors[J].Cell Microbiol,2013,15(10):1622-1631.
[23]Silva-Herzog E,Detweiler C S.Salmonella enterica replication in hemophagocytic macrophages requires two type three secretion systems[J].Infect Immun,2010,78(8):3369-3377.
[24]Song M,Sukovich D J,Ciccarelli L,et al.Control of type IIIprotein secretion using a minimal genetic system[J].Nat Commun,2017,8:14737.
[25]Wille T,Blank K,Schmidt C,et al.Gaussia princeps luciferase as a reporter for transcriptional activity,protein secretion,and protein-protein interactions in Salmonella enterica serovar typhimurium[J].Appl Environ Microbiol,2012,78(1):250-257.
[26]Grohmann E,Christie P J,Waksman G,et al.Type IV secretion in Gram negative and Gram positive bacteria[J].Mol Microbiol,2018,107(4):455-471.
[27]Aguilar J,Zupan J,Cameron T A,et al.Agrobacterium type IVsecretion system and its substrates form helical arrays around the circumference of virulence-induced cells[J].Proc Natl Acad Sci USA,2010,107(8):3758-3763.
[28]Gomisrüth F X,SolàM,De I C F,et al.Coupling factors in macromolecular type-IV secretion machineries[J].Curr Pharm Des,2004,10(13):1551-1565.
[29]Naroeni A,Jouy N,Ouahrani-Bettache S,et al.Brucella suisimpaired specific recognition of phagosomes by lysosomes due to phagosomal membrane modifications[J].Infect Immun,2001,69(1):486-493.
[30]Niu H,Kozjak-Pavlovic V,Rudel T,et al.Anaplasma phagocytophilum Ats-1 is imported into host cell mitochondria and interferes with apoptosis induction[J].PLoS Pathog,2010,6(2):e1000774.
[31]Hsu F,Zhu W,Brennan L,et al.Structural basis for substrate recognition by a unique Legionella phosphoinositide phosphatase[J].Proc Natl Acad Sci USA,2012,109(34):13567-13572.
[32]Barrozo R M,Cooke C L,Hansen L M,et al.Functional plasticity in the type IV secretion system of Helicobacter pylori[J].PLoS Pathog,2013,9(2):e1003189.
[33]Ghosal D,Chang Y W,Jeong K C,et al.In situ structure of the Legionella Dot/Icm type IV secretion system by electron cryotomography[J].EMBO Rep,2017,18(5):726-732.
[34]Souza D P,Oka G U,Alvarez-Martinez C E,et al.Bacterial killing via a type IV secretion system[J].Nat Commun,2015,6:6453.
[35]Gonzálezprieto C,Gabriel R,Dehio C,et al.The conjugative relaxase TrwC promotes integration of foreign DNA in the human genome[J].Appl Environ Microbiol,2017,83(12):e00207-17.
[36]Henderson I R,Navarrogarcia F,Desvaux M,et al.Type V protein secretion pathway:The autotransporter story[J].Microbiol Molecular Biol Rev,2004,68(4):692-744.
[37]Gawarzewski I,Smits S H,Schmitt L,et al.Structural comparison of the transport units of type V secretion systems[J].Biol Chem,2013,394(11):1385-1398.
[38]Desvaux M,Parham N J,Henderson I R.Type V protein secretion:simplicity gone awry[J].Curr Issues Mol Biol,2004,6(2):111-124.
[39]Salacha R,Kovacic F,Brochierarmanet C,et al.The Pseudomonas aeruginosa patatin-like protein PlpD is the archetype of a novel type V secretion system[J].Environ Microbiol,2010,12(6):1498-1512.
[40]Tsai J C,Yen M R,Castillo R,et al.The bacterial intimins and invasins:a large and novel family of secreted proteins[J].PLoSOne,2010,5(12):e14403.
[41]Albenne C,Ieva R.Job contenders:roles of theβbarrel assembly machinery and the translocation and assembly module in autotransporter secretion[J].Mol Microbiol,2017,106(4):505-517.
[42]Knowles T J,Scotttucker A,Overduin M,et al.Membrane protein architects:The role of the BAM complex in outer membrane protein assembly[J].Nat Rev Microbiol,2009,7(3):206-214.
[43]Fan E,Chauhan N,Udatha D B,et al.Type V secretion systems in bacteria[J].Microbiol Spectr,2016,4(1),doi:10.1128.
[44]Pukatzki S,Ma A T,Sturtevant D,et al.Identification of a conserved bacterial protein secretion system in Vibrio cholerae using the Dictyostelium host model system[J].Proc Natl Acad Sci USA,2006,103(5):1528-1533.
[45]Silverman J M,Brunet Y R.Cascales E,et al.Structure and regulation of the type VI secretion system[J].Annu Rev Microbiol,2012,66:453-472.
[46]Basler M,Pilhofer M,Henderson P G,et al.Type VI secretion requires a dynamic contractile phage tail-like structure[J].Nature,2012,483(7388):182-186.
[47]Weber B,Hasic M,Chen C,et al.Type VI secretion modulates quorum sensing and stress response in Vibrio anguillarum[J].Environ Microbiol,2009,11(12):3018-3028.
[48]Jani A J,Cotter P A.Type VI secretion:Not just for pathogenesis anymore[J].Cell Host Microbe,2010,8(1):2-6.
[49]Warne B,Harkins C P,Harris S R.et al.The Ess/Type VII secretion system of Staphylococcus aureus shows unexpected genetic diversity[J].BMC Genomics,2016,17(1):222.
[50]Simeone R,Bobard A,Lippmann J,et al.Phagosomal rupture by Mycobacterium tuberculosis results in toxicity and host cell death[J].PLo S Pathog,2012,8(2):e1002507.
[51]Bhat K H,Das A,Srikantam A,et al.PPE2 protein of Mycobacterium tuberculosis may inhibit nitric oxide in activated macrophages[J].Ann New Y Acad Sci,2013,1283(1):97-101.
[52]Mielichsüss B,Wagner R M,Mietrach N,et al.Flotillin scaffold activity contributes to type VII secretion system assembly in Staphylococcus aureus[J].PLo S Pathog,2017,13(11):e1006728.
[53]Guo Yun-qing,Di Hu,Guo Jie,et al.Riemerella anatipestifer Type IX secretion system is required for virulence and gelatinase secretion[J].Front Microbiol,2017,8:2553.
[54]Nenninger A A,Robinson L S,Hultgren S J.Localized and efficient curli nucleation requires the chaperone-like amyloid assembly protein CsgF[J].Proc Natl Acad Sci USA,2009,106(3):900-905.
[55]Loferer H,Hammar M,Normark S.Availability of the fibre subunit CsgA and the nucleator protein CsgB during assembly of fibronectin-binding curli is limited by the intracellular concentration of the novel lipoprotein CsgG[J].Mol Microbiol,1997,26(1):11-23.
[56]Bian Z,Normark S.Nucleator function of CsgB for the assembly of adhesive surface organelles in Escherichia coli[J].Embo J,1997,16(19):5827-5836.
[57]Biesecker S G,Nicastro L K,Wilson R P,et al.The functional amyloid curli protects Escherichia coli against complement-mediated bactericidal activity[J].Biomolecules,2018,8(1):E5.
[58]Hu Lan.Prevalence of curli genes among Cronobacter species and their roles in biofilm formation and cell-cell aggregation[J].Int J Food Microbiol,2018,265:65-73.
[59]Jain N,魡dén J,Nagamatsu K,et al.Inhibition of curli assembly and Escherichia coli biofilm formation by the human systemic amyloid precursor transthyretin[J].Proc Natl Acad Sci USA,2017,114(46):12184-12189.
[60]Heath J E,Seers C A,Veith P D,et al.PG1058 is a novel multidomain protein component of the bacterial Type IX secretion system[J].PLo S One,2016,11(10):e0164313.
[61]Taguchi Y,Sato K,Yukitake H,et al.Involvement of an Skp-Like Protein,PGN_0300,in the Type IX secretion system of porphyromonas gingivalis[J].Infect Immun,2015,84(1):230.
[62]Mcbride M J,Nakane D.Flavobacterium gliding motility and the type IX secretion system[J].Curr Opin Microbiol,2015,28:72-77.
[2]Abdallah A M,van Pittius N C,Champion P A,et al.Type VIIsecretion-Mycobacteria show the way[J].Nat Rev Microbiol,2007,5(11):883-891.
[3]Goebel W,Hedgpeth J.Cloning and functional characterization of the plasmid-encoded hemolysin determinant of Escherichia coli[J].J Bacteriol,1982,151(3):1290-1298.
[4]Morgan J L W,Acheson J F,Zimmer J.Structure of a Type-1secretion system ABC transporter[J].Structure,2017,25(3):522-529.
[5]Thomas S,Holland I B,Schmitt L.The Type 1 secretion pathway-The hemolysin system and beyond[J].Biochim Biophys Acta,2014,1843(8):1629-1641.
[6]Gerlach R G,J覿ckel D,Stecher B,et al.Salmonella pathogenicity island 4 encodes a giant non-fimbrial adhesin and the cognate type 1 secretion system[J].Cell Microbiol,2007,9(7):1834-1850.
[7]Yoshida K,Toyofuku M,Obana N,et al.Biofilm formation by Paracoccus denitrificans requires a type I secretion system-dependent adhesin Bap A[J].FEMS Microbiol Lett,2017,364(4),doi:10.1093.
[8]Harding C M,Pulido M R,Di V G,et al.Pathogenic acinetobacter species have a functional Type I secretion system and contact-dependent inhibition systems[J].J Bio Chem,2017,292(22):9075-9087.
[9]Lesic B,Starkey M,He J,et al.Quorum sensing differentially regulates Pseudomonas aeruginosa type VI secretion locus I and homologous loci II and III,which are required for pathogenesis[J].Microbiology,2009,155(9):2845-2855.
[10]Ferrandez Y,Condemine G.Novel mechanism of outer membrane targeting of proteins in Gram-negative bacteria[J].Mol Microbiol,2008,69(6):1349-1357.
[11]Pugsley A P.The complete general secretory pathway in gramnegative bacteria[J].Microbiol Rev,1993,57(1):50-108.
[12]Voulhoux R,Ball G,Ize B,et al.Involvement of the twin-arginine translocation system in protein secretion via the type IIpathway[J].EMBO J,2001,20(23):6735-6741.
[13]Pugsley A P,Possot O S N,Hardie K R,et al.Recent progress and future directions in studies of the main terminal branch of the general secretory pathway in gram-negative bacteria-a review[J].Gene,1997,192(1):13-19.
[14]Lory S.Secretion of proteins and assembly of bacterial surface organelles:Shared pathways of extracellular protein targeting[J].Curr Opin Microbiol,1998,1(1):27-35.
[15]Francetic O,Belin D,Badaut C,et al.Expression of the endogenous type II secretion pathway in Escherichia coli leads to chitinase secretion[J].EMBO J,2000,19(24):6697-6703.
[16]Corbett M,Virtue S,Bell K,et al.Identification of a new quorum-sensing-controlled virulence factor in Erwinia carotovora subsp.atroseptica secreted via the type II targeting pathway[J].Mol Plant Microbe Interact,2005,18(4):334-342.
[17]Ray S K,Rajeshwari R,Sonti R V.Mutants of Xanthomonas oryzae pv.oryzae deficient in general secretory pathway are virulence deficient and unable to secrete xylanase[J].Mol Plant Microbe Interact,2000,13(4):394-401.
[18]Kubori T,Matsushima Y,Dai N,et al.Supramolecular structure of the Salmonella typhimurium Type III protein secretion system[J].Science,1998,280(5363):602-605.
[19]Coburn B,Sekirov I,Finlay B B.Type III secretion systems and disease[J].Clin Microbiol Rev,2007,20(4):535-549.
[20]Van Gijsegem F,Gough C,Zischek C,et al.The hrp gene locus of Pseudomonas solanacearum,which controls the production of a type III secretion system,encodes eight proteins related to components of the bacterial flagellar biogenesis complex[J].Mol Microbiol,1995,15(6):1095-1114.
[21]Gaytán M O,Martínez-Santos V I,Soto E,et al.Type three secretion system in attaching and effacing pathogens[J].Front Cell Infect Microbiol,2016,6(21):129.
[22]Bliska J B,Wang X,Viboud G I,et al.Modulation of innate immune responses by Yersinia type III secretion system translocators and effectors[J].Cell Microbiol,2013,15(10):1622-1631.
[23]Silva-Herzog E,Detweiler C S.Salmonella enterica replication in hemophagocytic macrophages requires two type three secretion systems[J].Infect Immun,2010,78(8):3369-3377.
[24]Song M,Sukovich D J,Ciccarelli L,et al.Control of type IIIprotein secretion using a minimal genetic system[J].Nat Commun,2017,8:14737.
[25]Wille T,Blank K,Schmidt C,et al.Gaussia princeps luciferase as a reporter for transcriptional activity,protein secretion,and protein-protein interactions in Salmonella enterica serovar typhimurium[J].Appl Environ Microbiol,2012,78(1):250-257.
[26]Grohmann E,Christie P J,Waksman G,et al.Type IV secretion in Gram negative and Gram positive bacteria[J].Mol Microbiol,2018,107(4):455-471.
[27]Aguilar J,Zupan J,Cameron T A,et al.Agrobacterium type IVsecretion system and its substrates form helical arrays around the circumference of virulence-induced cells[J].Proc Natl Acad Sci USA,2010,107(8):3758-3763.
[28]Gomisrüth F X,SolàM,De I C F,et al.Coupling factors in macromolecular type-IV secretion machineries[J].Curr Pharm Des,2004,10(13):1551-1565.
[29]Naroeni A,Jouy N,Ouahrani-Bettache S,et al.Brucella suisimpaired specific recognition of phagosomes by lysosomes due to phagosomal membrane modifications[J].Infect Immun,2001,69(1):486-493.
[30]Niu H,Kozjak-Pavlovic V,Rudel T,et al.Anaplasma phagocytophilum Ats-1 is imported into host cell mitochondria and interferes with apoptosis induction[J].PLoS Pathog,2010,6(2):e1000774.
[31]Hsu F,Zhu W,Brennan L,et al.Structural basis for substrate recognition by a unique Legionella phosphoinositide phosphatase[J].Proc Natl Acad Sci USA,2012,109(34):13567-13572.
[32]Barrozo R M,Cooke C L,Hansen L M,et al.Functional plasticity in the type IV secretion system of Helicobacter pylori[J].PLoS Pathog,2013,9(2):e1003189.
[33]Ghosal D,Chang Y W,Jeong K C,et al.In situ structure of the Legionella Dot/Icm type IV secretion system by electron cryotomography[J].EMBO Rep,2017,18(5):726-732.
[34]Souza D P,Oka G U,Alvarez-Martinez C E,et al.Bacterial killing via a type IV secretion system[J].Nat Commun,2015,6:6453.
[35]Gonzálezprieto C,Gabriel R,Dehio C,et al.The conjugative relaxase TrwC promotes integration of foreign DNA in the human genome[J].Appl Environ Microbiol,2017,83(12):e00207-17.
[36]Henderson I R,Navarrogarcia F,Desvaux M,et al.Type V protein secretion pathway:The autotransporter story[J].Microbiol Molecular Biol Rev,2004,68(4):692-744.
[37]Gawarzewski I,Smits S H,Schmitt L,et al.Structural comparison of the transport units of type V secretion systems[J].Biol Chem,2013,394(11):1385-1398.
[38]Desvaux M,Parham N J,Henderson I R.Type V protein secretion:simplicity gone awry[J].Curr Issues Mol Biol,2004,6(2):111-124.
[39]Salacha R,Kovacic F,Brochierarmanet C,et al.The Pseudomonas aeruginosa patatin-like protein PlpD is the archetype of a novel type V secretion system[J].Environ Microbiol,2010,12(6):1498-1512.
[40]Tsai J C,Yen M R,Castillo R,et al.The bacterial intimins and invasins:a large and novel family of secreted proteins[J].PLoSOne,2010,5(12):e14403.
[41]Albenne C,Ieva R.Job contenders:roles of theβbarrel assembly machinery and the translocation and assembly module in autotransporter secretion[J].Mol Microbiol,2017,106(4):505-517.
[42]Knowles T J,Scotttucker A,Overduin M,et al.Membrane protein architects:The role of the BAM complex in outer membrane protein assembly[J].Nat Rev Microbiol,2009,7(3):206-214.
[43]Fan E,Chauhan N,Udatha D B,et al.Type V secretion systems in bacteria[J].Microbiol Spectr,2016,4(1),doi:10.1128.
[44]Pukatzki S,Ma A T,Sturtevant D,et al.Identification of a conserved bacterial protein secretion system in Vibrio cholerae using the Dictyostelium host model system[J].Proc Natl Acad Sci USA,2006,103(5):1528-1533.
[45]Silverman J M,Brunet Y R.Cascales E,et al.Structure and regulation of the type VI secretion system[J].Annu Rev Microbiol,2012,66:453-472.
[46]Basler M,Pilhofer M,Henderson P G,et al.Type VI secretion requires a dynamic contractile phage tail-like structure[J].Nature,2012,483(7388):182-186.
[47]Weber B,Hasic M,Chen C,et al.Type VI secretion modulates quorum sensing and stress response in Vibrio anguillarum[J].Environ Microbiol,2009,11(12):3018-3028.
[48]Jani A J,Cotter P A.Type VI secretion:Not just for pathogenesis anymore[J].Cell Host Microbe,2010,8(1):2-6.
[49]Warne B,Harkins C P,Harris S R.et al.The Ess/Type VII secretion system of Staphylococcus aureus shows unexpected genetic diversity[J].BMC Genomics,2016,17(1):222.
[50]Simeone R,Bobard A,Lippmann J,et al.Phagosomal rupture by Mycobacterium tuberculosis results in toxicity and host cell death[J].PLo S Pathog,2012,8(2):e1002507.
[51]Bhat K H,Das A,Srikantam A,et al.PPE2 protein of Mycobacterium tuberculosis may inhibit nitric oxide in activated macrophages[J].Ann New Y Acad Sci,2013,1283(1):97-101.
[52]Mielichsüss B,Wagner R M,Mietrach N,et al.Flotillin scaffold activity contributes to type VII secretion system assembly in Staphylococcus aureus[J].PLo S Pathog,2017,13(11):e1006728.
[53]Guo Yun-qing,Di Hu,Guo Jie,et al.Riemerella anatipestifer Type IX secretion system is required for virulence and gelatinase secretion[J].Front Microbiol,2017,8:2553.
[54]Nenninger A A,Robinson L S,Hultgren S J.Localized and efficient curli nucleation requires the chaperone-like amyloid assembly protein CsgF[J].Proc Natl Acad Sci USA,2009,106(3):900-905.
[55]Loferer H,Hammar M,Normark S.Availability of the fibre subunit CsgA and the nucleator protein CsgB during assembly of fibronectin-binding curli is limited by the intracellular concentration of the novel lipoprotein CsgG[J].Mol Microbiol,1997,26(1):11-23.
[56]Bian Z,Normark S.Nucleator function of CsgB for the assembly of adhesive surface organelles in Escherichia coli[J].Embo J,1997,16(19):5827-5836.
[57]Biesecker S G,Nicastro L K,Wilson R P,et al.The functional amyloid curli protects Escherichia coli against complement-mediated bactericidal activity[J].Biomolecules,2018,8(1):E5.
[58]Hu Lan.Prevalence of curli genes among Cronobacter species and their roles in biofilm formation and cell-cell aggregation[J].Int J Food Microbiol,2018,265:65-73.
[59]Jain N,魡dén J,Nagamatsu K,et al.Inhibition of curli assembly and Escherichia coli biofilm formation by the human systemic amyloid precursor transthyretin[J].Proc Natl Acad Sci USA,2017,114(46):12184-12189.
[60]Heath J E,Seers C A,Veith P D,et al.PG1058 is a novel multidomain protein component of the bacterial Type IX secretion system[J].PLo S One,2016,11(10):e0164313.
[61]Taguchi Y,Sato K,Yukitake H,et al.Involvement of an Skp-Like Protein,PGN_0300,in the Type IX secretion system of porphyromonas gingivalis[J].Infect Immun,2015,84(1):230.
[62]Mcbride M J,Nakane D.Flavobacterium gliding motility and the type IX secretion system[J].Curr Opin Microbiol,2015,28:72-77.