FtsQ is an essential cell division protein. It may link together the upstream cell division proteins, which are predominantly cytoplasmic, with the downstream cell division proteins, which are predominantly periplasmic [1]. FtsQ may control the correct divisome assembly [2]. DivIB is a cell division protein from Gram-positive bacteria, probably homologous to Escherichia coli FtsQ. DivIB interacts with FtsL, DivIC and PBP-2B [3,4]. DivIB plays an essential role in division at high temperatures, maybe by protecting FtsL from degradation or by promoting formation of the FtsL-DivIC complex [5]. It is also required for efficient sporulation at all temperatures [6]. FtsQ and DivIB have a short N-terminal cytoplasmic domain and a larger C-terminal periplasmic domain [2,4]. This entry represents the C-terminal region.

1: Three functional subdomains of the Escherichia coli FtsQ protein are involved in its interaction with the other division proteins. D'Ulisse V, Fagioli M, Ghelardini P, Paolozzi L; Microbiology (Reading). 2007;153:124-138. PMID:17185541

2: Divisome under construction: distinct domains of the small membrane protein FtsB are necessary for interaction with multiple cell division proteins. Gonzalez MD, Beckwith J; J Bacteriol. 2009;191:2815-2825. PMID:19233928

3: Multiple interactions between the transmembrane division proteins of Bacillus subtilis and the role of FtsL instability in divisome assembly. Daniel RA, Noirot-Gros MF, Noirot P, Errington J; J Bacteriol. 2006;188:7396-7404. PMID:16936019

4: Evidence from artificial septal targeting and site-directed mutagenesis that residues in the extracytoplasmic beta domain of DivIB mediate its interaction with the divisomal transpeptidase PBP 2B. Rowland SL, Wadsworth KD, Robson SA, Robichon C, Beckwith J, King GF; J Bacteriol. 2010;192:6116-6125. PMID:20870765

5: Intrinsic instability of the essential cell division protein FtsL of Bacillus subtilis and a role for DivIB protein in FtsL turnover. Daniel RA, Errington J; Mol Microbiol. 2000;36:278-289. PMID:10792716

6: Requirement for the cell division protein DivIB in polar cell division and engulfment during sporulation in Bacillus subtilis. Thompson LS, Beech PL, Real G, Henriques AO, Harry EJ; J Bacteriol. 2006;188:7677-7685. PMID:16936026