title: Synthesis of a Klebsiella pneumoniae O-antigen heteropolysaccharide (O12) requires an ABC 2 transporter.
abstract: A recombinant clone encoding enzymes for Klebsiella pneumoniae O12-antigen lipopolysaccharide (LPS) was found when we screened for serum resistance of a cosmid-based genomic library of K. pneumoniae KT776 (O12:K80) introduced into Escherichia coli DH5alpha. A total of eight open reading frames (ORFs) (wb(O12) gene cluster) were necessary to produce K. pneumoniae O12-antigen LPS in E. coli K-12. A complete analysis of the K. pneumoniae wb(O12) cluster revealed an interesting coincidence with the wb(O4) cluster of Serratia marcescens from ORF5 to ORF8 (or WbbL to WbbA). This prompted us to generate mutants of K. pneumoniae strain KT776 (O12) and to study complementation between the two enterobacterial wb clusters using mutants of S. marcescens N28b (O4) obtained previously. Both wb gene clusters are examples of ABC 2 transporter-dependent pathways for O-antigen heteropolysaccharides. The wzm-wzt genes and the wbbA or wbbB genes were not interchangeable between the two gene clusters despite their high level of similarity. However, introduction of three cognate genes (wzm-wzt-wbbA or wzm-wzt-wbbB) into mutants unable to produce O antigen allowed production of the specific O antigen. The K. pneumoniae O12 WbbL protein performs the same function as WbbL from S. marcescens O4 in either the S. marcescens O4 or E. coli K-12 genetic background.
authors.affiliation: Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, 08071 Barcelona, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Izquierdo
authors.forename: Susana
authors.initials: S
authors.lastname: Merino
authors.forename: Miguel
authors.initials: M
authors.lastname: Regué
authors.forename: Florencia
authors.initials: F
authors.lastname: Rodriguez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Tomás
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005816:Genetic Complementation Test; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D019081:O Antigens / Q000096:biosynthesis*; D020539:Sequence Analysis, Protein; D012689:Sequence Homology, Nucleic Acid; D012706:Serratia marcescens / Q000235:genetics
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D019081:O Antigens; C472370:Wzm protein, Klebsiella pneumoniae; C472371:Wzt protein, Klebsiella pneumoniae