title: Insertions in the OCL1 locus of Acinetobacter baumannii lead to shortened lipooligosaccharides.
abstract: Genomes of 82 Acinetobacter baumannii global clones 1 (GC1) and 2 (GC2) isolates were sequenced and different forms of the locus predicted to direct synthesis of the outer core (OC) of the lipooligosaccharide were identified. OCL1 was in all GC2 genomes, whereas GC1 isolates carried OCL1, OCL3 or a new locus, OCL5. Three mutants in which an insertion sequence (ISAba1 or ISAba23) interrupted OCL1 were identified. Isolates with OCL1 intact produced only lipooligosaccharide, while the mutants produced lipooligosaccharide of reduced molecular weight. Thus, the assignment of the OC locus as that responsible for the synthesis of the OC is correct.
authors.affiliation: School of Molecular Bioscience, The University of Sydney, New South Wales, Australia. Electronic address: johanna.kenyon@sydney.edu.au.
authors.forename: Johanna J
authors.initials: JJ
authors.lastname: Kenyon
authors.affiliation: Department of Biochemistry and Molecular Biology, and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia.
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Holt
authors.affiliation: Wellcome Sanger Trust Institute, Hinxton, Cambridge, United Kingdom.
authors.forename: Derek
authors.initials: D
authors.lastname: Pickard
authors.affiliation: Wellcome Sanger Trust Institute, Hinxton, Cambridge, United Kingdom.
authors.forename: Gordon
authors.initials: G
authors.lastname: Dougan
authors.affiliation: School of Molecular Bioscience, The University of Sydney, New South Wales, Australia. Electronic address: ruth.hall@sydney.edu.au.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Hall
mesh_terms: D040981:Acinetobacter baumannii / Q000235:genetics*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D056426:Genetic Loci; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016254:Mutagenesis, Insertional; D017422:Sequence Analysis, DNA
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides
keywords: ISAba1; ISAba23; Lipid A; Lipooligosaccharide; OC locus; Outer core oligosaccharide