title: Topological characterization of the essential Escherichia coli cell division protein FtsW.
abstract: The membrane topology of Escherichia coli FtsW, a 46-kDa essential protein, was analyzed using a set of 28 ftsW-alkaline phosphatase (ftsW-phoA) and nine ftsW-beta-lactamase (ftsW-bla) gene fusions obtained by in vivo and in vitro methods. The alkaline phosphatase activities or resistance pattern of cells expressing the FtsW-PhoA or FtsW-Bla fusions confirmed only eight out of 10 transmembrane segments predicted by computational methods. After comparison with the recent topology of Streptococcus pneumoniae FtsW, we could identify all the fusions in absolute agreement with the predicted model: N-terminal and C-terminal ends in the cytoplasm, 10 transmembrane segments and one large loop of 67 amino acids (E240-E306) located in the periplasm.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Lara
authors.forename: Juan A
authors.initials: JA
authors.lastname: Ayala
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics; D000595:Amino Acid Sequence; D019677:Artificial Gene Fusion; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; C061684:FtsW protein, Bacteria; D000469:Alkaline Phosphatase; D001618:beta-Lactamases