title: Fine-mapping the contact sites of the Escherichia coli cell division proteins FtsB and FtsL on the FtsQ protein.
abstract: Escherichia coli cell division is effected by a large assembly of proteins called the divisome, of which a subcomplex consisting of three bitopic inner membrane proteins, FtsQ, FtsB, and FtsL, is an essential part. These three proteins, hypothesized to link cytoplasmic to periplasmic events during cell division, contain large periplasmic domains that are of major importance for function and complex formation. The essential nature of this subcomplex, its low abundance, and its multiple interactions with key divisome components in the relatively accessible periplasm make it an attractive target for the development of protein-protein interaction inhibitors. Although the crystal structure of the periplasmic domain of FtsQ has been solved, the structure of the FtsQBL complex is unknown, with only very crude indications of the interactions in this complex. In this study, we used in vivo site-specific photo cross-linking to probe the surface of the FtsQ periplasmic domain for its interaction interfaces with FtsB and FtsL. An interaction hot spot for FtsB was identified around residue Ser-250 in the C-terminal region of FtsQ and a membrane-proximal interaction region for both proteins around residue Lys-59. Sequence alignment revealed a consensus motif overlapping with the C-terminal interaction hot spot, underlining the importance of this region in FtsQ. The identification of contact sites in the FtsQBL complex will guide future development of interaction inhibitors that block cell division.
authors.affiliation: Section of Molecular Microbiology, Department of Molecular Cell Biology, Amsterdam Institute of Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands.
authors.forename: H Bart
authors.initials: HB
authors.lastname: van den Berg van Saparoea
authors.forename: Marjolein
authors.initials: M
authors.lastname: Glas
authors.forename: Ingrid G W H
authors.initials: IG
authors.lastname: Vernooij
authors.forename: Wilbert
authors.initials: W
authors.lastname: Bitter
authors.forename: Tanneke
authors.initials: T
authors.lastname: den Blaauwen
authors.forename: Joen
authors.initials: J
authors.lastname: Luirink
mesh_terms: D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D004926:Escherichia coli / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010449:Peptide Mapping / Q000379:methods; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
chemical_list: D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; C456028:FtsB protein, E coli; C068023:FtsQ protein, E coli; D008565:Membrane Proteins; D046912:Multiprotein Complexes; C078387:ftsL protein, E coli
keywords: Benzoylphenylalanine; Cell Division; Divisome; Escherichia coli; Photo Cross-linking; Protein Complexes; Protein Cross-linking; Protein-Protein Interactions