SepF increases the assembly and bundling of FtsZ polymers and stabilizes FtsZ protofilaments by binding along its length.
SepF (Septum Forming) protein has been recently identified through genetic studies, and it has been suggested to be involved in the division of Bacillus subtilis cells. We have purified functional B. subtilis SepF from the inclusion bodies overexpressed in Escherichia coli. Far-UV circular dichroism and fluorescence spectroscopic analysis involving the extrinsic fluorescent probe 1-anilinonaphthalene-8-sulfonic acid suggested that the purified SepF had characteristics of folded proteins. SepF was found to promote the assembly and bundling of FtsZ protofilaments using three complimentary techniques, namely 90 degrees light scattering, sedimentation, and transmission electron microscopy. SepF also decreased the critical concentration of FtsZ assembly, prevented the dilution-induced disassembly of FtsZ protofilaments, and suppressed the GTPase activity of FtsZ. Further, thick bundles of FtsZ protofilaments were observed using fluorescein isothiocyanate-labeled SepF (FITC-SepF). Interestingly, FITC-SepF was found to be uniformly distributed along the length of the FtsZ protofilaments, suggesting that SepF copolymerizes with FtsZ. SepF formed a stable complex with FtsZ, as evident from the gel filtration analysis. Using a C-terminal tail truncated FtsZ (FtsZDelta16) and a C-terminal synthetic peptide of B. subtilis FtsZ (366-382); we provided evidence indicating that SepF binds primarily to the C-terminal tail of FtsZ. The present work in concert with the available in vivo data support a model in which SepF plays an important role in regulating the assembly dynamics of the divisome complex; therefore, it may have an important role in bacterial cell division.
Singh
Jay Kumar
JK
School of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
Makde
Ravindra D
RD
Kumar
Vinay
V
Panda
Dulal
D
D000817:Anilino Naphthalenesulfonates / Q000737:chemistry*; D001412:Bacillus subtilis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000502:physiology*; D002942:Circular Dichroism / Q000379:methods; D003598:Cytoskeletal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D015870:Gene Expression; D006004:Glycogen Debranching Enzyme System / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D017510:Protein Folding; D017434:Protein Structure, Tertiary / Q000502:physiology
D000817:Anilino Naphthalenesulfonates; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; D006004:Glycogen Debranching Enzyme System; D046912:Multiprotein Complexes; C027132:1-anilino-8-naphthalenesulfonate; C020569:4 alpha-glucanotransferase
Mol Microbiol. 2005 Mar;55(6):1722-34
15752196
Anal Biochem. 1976 May 7;72:248-54
942051
J Bacteriol. 2005 Sep;187(18):6536-44
16159787
Cell. 1997 Jan 24;88(2):175-85
9008158
Biophys Chem. 2007 Apr;127(1-2):1-8
17257734
Nat Rev Microbiol. 2005 Dec;3(12):959-68
16322744
J Bacteriol. 1999 Dec;181(24):7531-44
10601211
Cell. 2001 Mar 23;104(6):913-22
11290328
Mol Microbiol. 2002 Mar;43(6):1517-21
11952901
J Biol Chem. 2004 Jun 18;279(25):25959-65
15039432
Annu Rev Microbiol. 2003;57:125-54
14527275
Mol Microbiol. 2001 Apr;40(1):115-25
11298280
Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):4197-202
12634424
Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9642-7
10449747
Curr Biol. 2003 Jan 8;13(1):R16-8
12526758
Cell Motil Cytoskeleton. 1998;40(1):71-86
9605973
J Mol Biol. 2004 Aug 13;341(3):839-52
15288790
Genes Dev. 2002 Oct 1;16(19):2544-56
12368265
J Bacteriol. 2003 Oct;185(20):6209-14
14526035
Annu Rev Biochem. 2006;75:467-92
16756499
Science. 2008 May 9;320(5877):792-4
18420899
Biochemistry. 2007 Sep 25;46(38):11013-22
17718511
Mol Microbiol. 1993 Feb;7(4):601-10
8459776
Mol Microbiol. 2005 Jul;57(1):238-49
15948963
EMBO J. 2002 Feb 15;21(4):685-93
11847116
Anal Biochem. 1991 Jan;192(1):112-6
1646572
EMBO J. 1997 Sep 1;16(17):5455-63
9312004
J Biol Chem. 2003 Feb 7;278(6):3735-41
12446699
Protein Eng. 1992 Apr;5(3):191-5
1409538
Mol Microbiol. 2006 Feb;59(3):989-99
16420366
J Biol Chem. 2003 Jun 13;278(24):21336-43
12649276
Mol Microbiol. 1997 Jun;24(5):905-15
9219999
J Biol Chem. 2007 Dec 28;282(52):37515-28
17977836
Proc Natl Acad Sci U S A. 1999 Apr 27;96(9):4971-6
10220403
J Bacteriol. 1997 Sep;179(17):5551-9
9287012
Mol Microbiol. 2000 Jul;37(2):410-23
10931335
BMC Bioinformatics. 2006 May 16;7:255
16704727
Res Microbiol. 1990 Jan;141(1):39-49
2194248
Mol Microbiol. 2006 Jun;60(6):1364-80
16796675