title: Structural determinants required to target penicillin-binding protein 3 to the septum of Escherichia coli.
abstract: In Escherichia coli, cell division is mediated by the concerted action of about 12 proteins that assemble at the division site to presumably form a complex called the divisome. Among these essential division proteins, the multimodular class B penicillin-binding protein 3 (PBP3), which is specifically involved in septal peptidoglycan synthesis, consists of a short intracellular M1-R23 peptide fused to a F24-L39 membrane anchor that is linked via a G40-S70 peptide to an R71-I236 noncatalytic module itself linked to a D237-V577 catalytic penicillin-binding module. On the basis of localization analyses of PBP3 mutants fused to green fluorescent protein by fluorescence microscopy, it appears that the first 56 amino acid residues of PBP3 containing the membrane anchor and the G40-E56 peptide contain the structural determinants required to target the protein to the cell division site and that none of the putative protein interaction sites present in the noncatalytic module are essential for the positioning of the protein to the division site. Based on the effects of increasing production of FtsQ or FtsW on the division of cells expressing PBP3 mutants, it is suggested that these proteins could interact. We postulate that FtsQ could play a role in regulating the assembly of these division proteins at the division site and the activity of the peptidoglycan assembly machineries within the divisome.
authors.affiliation: Centre d'Ingénierie des Protéines, Université de Liège, Institut de Chimie, B6a, B-4000 Liège, Belgium.
authors.forename: André
authors.initials: A
authors.lastname: Piette
authors.forename: Claudine
authors.initials: C
authors.lastname: Fraipont
authors.forename: Tanneke
authors.initials: T
authors.lastname: Den Blaauwen
authors.forename: Mirjam E G
authors.initials: ME
authors.lastname: Aarsman
authors.forename: Soumya
authors.initials: S
authors.lastname: Pastoret
authors.forename: Martine
authors.initials: M
authors.lastname: Nguyen-Distèche
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002473:Cell Wall / Q000201:enzymology / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D006602:Hexosyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan / Q000096:biosynthesis; D046928:Peptidoglycan Glycosyltransferase; D010458:Peptidyl Transferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary / Q000235:genetics / Q000502:physiology; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C478704:FtsI protein, E coli; C068023:FtsQ protein, E coli; D008164:Luminescent Proteins; D008565:Membrane Proteins; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; D011993:Recombinant Fusion Proteins; C061684:FtsW protein, Bacteria; D049452:Green Fluorescent Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D046928:Peptidoglycan Glycosyltransferase; D002267:Muramoylpentapeptide Carboxypeptidase