title: Full-length Escherichia coli SecA dimerizes in a closed conformation in solution as determined by cryo-electron microscopy.
abstract: SecA is an obligatory component of the Escherichia coli general secretion pathway. However, the oligomeric structure of SecA and SecA conformational changes during translocation processes are still unclear. Here we obtained the three-dimensional structure of E. coli wild-type full-length SecA in solution by single particle cryo-electron microscopy and determined its oligomeric organization. In this structure, SecA occurs as a dimer in which the two protomers are arranged in an antiparallel mode, with a novel electrostatic interface, and both protomers are in closed conformation. The system developed here may provide a promising technique for studying dynamic structural changes in SecA.
authors.affiliation: Department of Biological Sciences and Biotechnology, the State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Xijiang
authors.initials: X
authors.lastname: Pan
authors.forename: Ying
authors.initials: Y
authors.lastname: Tang
authors.forename: Shu
authors.initials: S
authors.lastname: Quan
authors.forename: Phang C
authors.initials: PC
authors.lastname: Tai
authors.forename: Sen-Fang
authors.initials: SF
authors.lastname: Sui
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D020285:Cryoelectron Microscopy / Q000379:methods*; D019281:Dimerization; D004926:Escherichia coli / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000737:chemistry*; D008968:Molecular Conformation; D011487:Protein Conformation; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D055672:Static Electricity
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins
references.citation: Cell. 1988 Nov 18;55(4):683-92
references.pmid: 2846186
references.citation: Science. 2002 Sep 20;297(5589):2018-26
references.pmid: 12242434
references.citation: Cell. 2007 Nov 16;131(4):756-69
references.pmid: 18022369
references.citation: J Biol Chem. 2003 Feb 7;278(6):3628-38
references.pmid: 12403785
references.citation: J Biol Chem. 1996 Nov 22;271(47):29698-706
references.pmid: 8939903
references.citation: EMBO J. 2002 Sep 2;21(17):4470-9
references.pmid: 12198149
references.citation: J Mol Biol. 2006 Dec 1;364(3):248-58
references.pmid: 17059823
references.citation: J Biol Chem. 1996 Nov 22;271(47):29514-6
references.pmid: 8939874
references.citation: J Mol Biol. 2007 Mar 9;366(5):1545-57
references.pmid: 17229438
references.citation: J Biol Chem. 2000 Aug 4;275(31):24191-8
references.pmid: 10807917
references.citation: Proc Natl Acad Sci U S A. 2004 Jul 27;101(30):10937-42
references.pmid: 15256599
references.citation: J Struct Biol. 1999 Dec 1;128(1):82-97
references.pmid: 10600563
references.citation: J Mol Graph. 1996 Feb;14(1):33-8, 27-8
references.pmid: 8744570
references.citation: Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4221-6
references.pmid: 12642659
references.citation: EMBO J. 1989 Mar;8(3):955-9
references.pmid: 2542028
references.citation: Biochemistry. 1993 Dec 7;32(48):13190-7
references.pmid: 8241173
references.citation: EMBO J. 1997 Dec 15;16(24):7297-304
references.pmid: 9405359
references.citation: J Struct Biol. 2007 Jul;159(1):149-53
references.pmid: 17419072
references.citation: Cell. 1981 Sep;25(3):765-72
references.pmid: 7026050
references.citation: Cell Mol Life Sci. 2003 Oct;60(10):2034-52
references.pmid: 14618254
references.citation: Proc Natl Acad Sci U S A. 2003 Mar 4;100(5):2243-8
references.pmid: 12606717
references.citation: J Mol Biol. 2006 Dec 1;364(3):259-65
references.pmid: 16989859
references.citation: J Struct Biol. 1996 Jan-Feb;116(1):190-9
references.pmid: 8742743
references.citation: Proc Natl Acad Sci U S A. 1993 Oct 1;90(19):9011-5
references.pmid: 8415645
references.citation: Biochemistry. 2003 Jul 29;42(29):8729-38
references.pmid: 12873133
references.citation: Protein Sci. 2002 Apr;11(4):875-82
references.pmid: 11910030
references.citation: Structure. 2001 Sep;9(9):779-88
references.pmid: 11566128
references.citation: Mol Microbiol. 2000 Jul;37(2):226-38
references.pmid: 10931320
references.citation: Biochem Biophys Res Commun. 1991 Jan 15;174(1):211-6
references.pmid: 1824919
references.citation: Cell. 1990 Oct 19;63(2):269-79
references.pmid: 2170023
references.citation: J Biol Chem. 1991 Dec 25;266(36):24596-600
references.pmid: 1837025