|Gene:||ftsB||Accession Numbers: G7424 (EcoCyc), b2748, ECK2743|
Component of: FtsLBQ cell division complex (summary available)
FtsB is an essential cell division protein which localizes to the cell division site. Depletion of FtsB results in abnormal filamentous morphology, but does not cause a defect in segregation of replicated DNA [Buddelmeijer02].
Localization of FtsB to the division site is dependent on FtsQ and FtsL, but does not require FtsW and FtsI. Conversely, FtsB is required for localization of FtsI and FtsW to the Z ring [Buddelmeijer02]. Although the hierarchy of dependency in the assembly of cell division proteins is largely linear, recent results showed that assembly of the cell division machinery is complex. Premature targeting of FtsB to the division site enables recruitment of FtsL, FtsW and FtsI in the absence of FtsQ [Goehring06].
FtsB contains a small N-terminal cytoplasmic domain, a membrane-spanning region and a periplasmic C-terminal domain with a leucine zipper motif [Buddelmeijer02]. The transmembrane domain homo-oligomerizes; the interaction is mediated by and polar amino acids on one face of the helix and hydrogen bonding of Gln16 [LaPointe13]. A crystal structure of the periplasmic domain has been solved, showing a canonical coiled-coil structure [LaPointe13].
FtsB and FtsL localization to the constriction site is codependent [Buddelmeijer02]; the periplasmic leucine zipper motif is required for optimal interaction between FtsL and FtsB [Robichon11]. FtsQ, FtsL and FtsB form a complex in vivo even in the absence of FtsK and thus independently of their localization to the septal region [Buddelmeijer04]. The N-terminal half of FtsB including parts of the periplasmic coiled-coil domain is required for its interaction with FtsL; in the complex with FtsL, this region is also sufficient for recruitment of downstream division proteins [Gonzalez09]. The transmembrane helices of FtsB and FtsL appear to be major contributors to the stability of a 1:1 higher-order oligomeric complex between FtsB and FtsL [Khadria13]. A part of the periplasmic C-terminal domain is required for interaction with FtsQ [Gonzalez09].
Overexpression of ftsB can partially suppress the viability and cell division phenotypes of an ftsK mutant [Geissler05].
Locations: inner membrane
|Map Position: [2,870,531 <- 2,870,842] (61.87 centisomes, 223°)||Length: 312 bp / 103 aa|
Molecular Weight of Polypeptide: 11.622 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0009019 , DIP:DIP-12117N , EchoBASE:EB2914 , EcoGene:EG13111 , EcoliWiki:b2748 , OU-Microarray:b2748 , PortEco:ftsB , PR:PRO_000022715 , Pride:P0A6S5 , Protein Model Portal:P0A6S5 , RefSeq:NP_417228 , RegulonDB:G7424 , SMR:P0A6S5 , String:511145.b2748 , UniProt:P0A6S5
|Biological Process:||GO:0043093 - FtsZ-dependent cytokinesis
GO:0051301 - cell division [UniProtGOA11, Ricard73, Buddelmeijer02]
GO:0007049 - cell cycle [UniProtGOA11, GOA01a]
|Molecular Function:||GO:0005515 - protein binding
[Rajagopala14, Robichon11, Gonzalez10, Gonzalez09, Scheffers07, DUlisse07, Karimova05, Buddelmeijer04]
GO:0042802 - identical protein binding [LaPointe13]
|Cellular Component:||GO:0030428 - cell septum
GO:0032155 - cell division site part [Buddelmeijer02]
GO:0005886 - plasma membrane [UniProtGOA11a, UniProtGOA11]
GO:0005887 - integral component of plasma membrane [GOA06]
GO:0016020 - membrane [UniProtGOA11]
GO:0016021 - integral component of membrane [UniProtGOA11]
GO:0032153 - cell division site [GOA06]
|MultiFun Terms:||cell processes → cell division|
|Growth Medium||Growth?||T (°C)||O2||pH||Osm/L||Growth Observations|
|LB Lennox||No||37||Aerobic||7||No [Baba06, Comment 1]|
Subunit of: FtsLBQ cell division complex
Subunit composition of
FtsLBQ cell division complex = [FtsQ][FtsB][FtsL]
essential cell division protein FtsQ = FtsQ (extended summary available)
essential cell division protein FtsB = FtsB (extended summary available)
essential cell division protein FtsL = FtsL (extended summary available)
The FtsL, FtsB and FtsQ cell division proteins form a complex independently of its location at the cell division site [Buddelmeijer04]. This complex is thought to function as a molecular scaffold that enables proper formation of the divisome.
A structural model of the periplasmic component of the FtsLBQ complex has been generated, indicating a trimeric or hexameric coiled-coil structure [Villanelo11]. A current hypothesis is that a dimer of FtsB recruits FtsL into a higher-order complex with 1:1 stoichiometry [Khadria13].
|Transmembrane-Region||4 -> 21|
|Protein-Segment||41 -> 72|
Peter D. Karp on Thu Jan 16, 2003:
Predicted gene function revised as a result of E. coli genome reannotation by Serres et al. [Serres01 ].
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.
Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554
Buddelmeijer02: Buddelmeijer N, Judson N, Boyd D, Mekalanos JJ, Beckwith J (2002). "YgbQ, a cell division protein in Escherichia coli and Vibrio cholerae, localizes in codependent fashion with FtsL to the division site." Proc Natl Acad Sci U S A 2002;99(9);6316-21. PMID: 11972052
Buddelmeijer04: Buddelmeijer N, Beckwith J (2004). "A complex of the Escherichia coli cell division proteins FtsL, FtsB and FtsQ forms independently of its localization to the septal region." Mol Microbiol 52(5);1315-27. PMID: 15165235
DUlisse07: D'Ulisse V, Fagioli M, Ghelardini P, Paolozzi L (2007). "Three functional subdomains of the Escherichia coli FtsQ protein are involved in its interaction with the other division proteins." Microbiology 153(Pt 1);124-38. PMID: 17185541
Geissler05: Geissler B, Margolin W (2005). "Evidence for functional overlap among multiple bacterial cell division proteins: compensating for the loss of FtsK." Mol Microbiol 58(2);596-612. PMID: 16194242
Goehring06: Goehring NW, Gonzalez MD, Beckwith J (2006). "Premature targeting of cell division proteins to midcell reveals hierarchies of protein interactions involved in divisome assembly." Mol Microbiol 61(1);33-45. PMID: 16824093
Gonzalez09: Gonzalez MD, Beckwith J (2009). "Divisome under construction: distinct domains of the small membrane protein FtsB are necessary for interaction with multiple cell division proteins." J Bacteriol 191(8);2815-25. PMID: 19233928
Gonzalez10: Gonzalez MD, Akbay EA, Boyd D, Beckwith J (2010). "Multiple interaction domains in FtsL, a protein component of the widely conserved bacterial FtsLBQ cell division complex." J Bacteriol 192(11);2757-68. PMID: 20363951
Karimova05: Karimova G, Dautin N, Ladant D (2005). "Interaction network among Escherichia coli membrane proteins involved in cell division as revealed by bacterial two-hybrid analysis." J Bacteriol 187(7);2233-43. PMID: 15774864
LaPointe13: LaPointe LM, Taylor KC, Subramaniam S, Khadria A, Rayment I, Senes A (2013). "Structural organization of FtsB, a transmembrane protein of the bacterial divisome." Biochemistry 52(15);2574-85. PMID: 23520975
Rajagopala14: Rajagopala SV, Sikorski P, Kumar A, Mosca R, Vlasblom J, Arnold R, Franca-Koh J, Pakala SB, Phanse S, Ceol A, Hauser R, Siszler G, Wuchty S, Emili A, Babu M, Aloy P, Pieper R, Uetz P (2014). "The binary protein-protein interaction landscape of Escherichia coli." Nat Biotechnol 32(3);285-90. PMID: 24561554
Ricard73: Ricard M, Hirota Y (1973). "Process of cellular division in Escherichia coli: physiological study on thermosensitive mutants defective in cell division." J Bacteriol 116(1);314-22. PMID: 4583216
Robichon11: Robichon C, Karimova G, Beckwith J, Ladant D (2011). "Role of leucine zipper motifs in association of the Escherichia coli cell division proteins FtsL and FtsB." J Bacteriol 193(18);4988-92. PMID: 21784946
Scheffers07: Scheffers DJ, Robichon C, Haan GJ, den Blaauwen T, Koningstein G, van Bloois E, Beckwith J, Luirink J (2007). "Contribution of the FtsQ transmembrane segment to localization to the cell division site." J Bacteriol 189(20);7273-80. PMID: 17693520
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