In vivo cross-linking of EpsG to EpsL suggests a role for EpsL as an ATPase-pseudopilin coupling protein in the Type II secretion system of Vibrio cholerae.
The type II secretion system is a multi-protein complex that spans the cell envelope of Gram-negative bacteria and promotes the secretion of proteins, including several virulence factors. This system is homologous to the type IV pilus biogenesis machinery and contains five proteins, EpsG-K, termed the pseudopilins that are structurally homologous to the type IV pilins. The major pseudopilin EpsG has been proposed to form a pilus-like structure in an energy-dependent process that requires the ATPase, EpsE. A key remaining question is how the membrane-bound EpsG interacts with the cytoplasmic ATPase, and if this is a direct or indirect interaction. Previous studies have established an interaction between the bitopic inner membrane protein EpsL and EpsE; therefore, in this study we used in vivo cross-linking to test the hypothesis that EpsG interacts with EpsL. Our findings suggest that EpsL may function as a scaffold to link EpsG and EpsE and thereby transduce the energy generated by ATP hydrolysis to support secretion. The recent discovery of structural homology between EpsL and a protein in the type IV pilus system implies that this interaction may be conserved and represent an important functional interaction for both the type II secretion and type IV pilus systems.
University of Michigan Medical School, Department of Microbiology and Immunology, Ann Arbor, MI 48109, USA.
Miranda D
MD
Gray
Michael
M
Bagdasarian
Wim G J
WG
Hol
Maria
M
Sandkvist
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000378:metabolism*; D036781:Fimbriae Proteins / Q000378:metabolism*; D047468:Immunoprecipitation; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D013912:Threonine / Q000378:metabolism; D014734:Vibrio cholerae / Q000201:enzymology*
D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D036781:Fimbriae Proteins; D013912:Threonine; D000251:Adenosine Triphosphatases
J Bacteriol. 1997 Nov;179(22):6994-7003
9371445
J Bacteriol. 2009 May;191(9):3149-61
19251862
J Bacteriol. 2007 Mar;189(5):1783-93
17158657
J Mol Biol. 2005 May 13;348(4):845-55
15843017
Mol Microbiol. 2008 May;68(4):827-37
18399938
J Biomed Sci. 2005;12(4):587-99
16078004
Mol Microbiol. 2004 Nov;54(3):647-64
15491357
J Mol Biol. 2009 Nov 20;394(1):143-59
19857646
J Bacteriol. 2007 Mar;189(5):2069-76
17172336
Mol Microbiol. 1998 Jan;27(1):221-33
9466269
FEMS Microbiol Lett. 2006 Feb;255(2):175-86
16448494
J Biol Chem. 2009 Dec 11;284(50):34580-9
19828448
J Bacteriol. 1978 Jun;134(3):1141-56
149110
Infect Immun. 1999 Mar;67(3):1393-404
10024587
Proc Natl Acad Sci U S A. 1984 Dec;81(24):7752-6
6393126
J Mol Biol. 2008 Mar 14;377(1):91-103
18241884
Trends Microbiol. 2005 Dec;13(12):581-8
16216510
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2404-8
8096341
Mol Microbiol. 1993 Jul;9(2):295-308
8412682
J Mol Biol. 2009 Nov 20;394(1):128-42
19857645
J Mol Biol. 2004 Nov 26;344(3):619-33
15533433
Gene. 1986;48(1):119-31
3549457
Nature. 1968 Mar 23;217(5134):1110-4
4868368
J Bacteriol. 2003 May;185(9):2749-58
12700254
EMBO J. 2007 Jan 10;26(1):19-27
17159897
Mol Microbiol. 2001 Apr;40(2):271-83
11309111
J Bacteriol. 1990 Jun;172(6):2911-9
1971619
J Bacteriol. 2007 Jun;189(12):4401-9
17434972
J Mol Biol. 1980 Apr;138(2):179-207
6997493
Mol Microbiol. 1993 Oct;10(2):233-43
7934814
J Biol Chem. 2009 Sep 18;284(38):25466-70
19640838
EMBO J. 1995 Apr 18;14(8):1664-73
7737119
J Biol Chem. 2005 Sep 9;280(36):31378-89
16012171
Mol Microbiol. 2006 Sep;61(6):1510-22
16968224
EMBO J. 2003 May 1;22(9):1969-80
12727865
J Bacteriol. 2007 Dec;189(23):8484-95
17890307
Biochem J. 2002 Jul 1;365(Pt 1):205-11
11931643
J Bacteriol. 2005 Jan;187(1):249-56
15601709
Structure. 2007 Mar;15(3):363-76
17355871
Proc Natl Acad Sci U S A. 2010 Jul 20;107(29):13081-6
20616068
Biochim Biophys Acta. 2004 Nov 11;1694(1-3):163-79
15546665
J Bacteriol. 2000 Feb;182(3):742-8
10633109
Mol Microbiol. 1998 Sep;29(6):1481-92
9781884
J Struct Biol. 2010 Jan;169(1):75-80
19747550
J Mol Biol. 2003 Oct 24;333(3):657-74
14556751
EMBO Rep. 2001 Mar;2(3):244-8
11266368
Infect Immun. 1996 Jul;64(7):2853-6
8698524
J Biomed Biotechnol. 2003;2003(3):202-207
12975535
EMBO J. 2007 Feb 7;26(3):878-90
17255937
Proc Natl Acad Sci U S A. 2001 Feb 27;98(5):2503-8
11226268
J Bacteriol. 1993 Jul;175(14):4375-82
8331069
J Bacteriol. 1999 May;181(10):3129-35
10322014
J Bacteriol. 2007 Dec;189(24):9082-9
17921296
Nat Struct Mol Biol. 2008 May;15(5):462-8
18438417
Curr Opin Struct Biol. 2008 Apr;18(2):267-77
18249533
J Bacteriol. 2003 Jun;185(11):3416-28
12754241
Res Microbiol. 2004 Mar;155(2):71-5
14990257
J Mol Biol. 2010 Jul 30;400(5):1011-21
20595000
Infect Immun. 2001 Jun;69(6):3523-35
11349009