title: O-antigen and core carbohydrate of Vibrio fischeri lipopolysaccharide: composition and analysis of their role in Euprymna scolopes light organ colonization.
abstract: Vibrio fischeri exists in a symbiotic relationship with the Hawaiian bobtail squid, Euprymna scolopes, where the squid provides a home for the bacteria, and the bacteria in turn provide camouflage that helps protect the squid from night-time predators. Like other gram-negative organisms, V. fischeri expresses lipopolysaccharide (LPS) on its cell surface. The structure of the O-antigen and the core components of the LPS and their possible role in colonization of the squid have not previously been determined. In these studies, an O-antigen ligase mutant, waaL, was utilized to determine the structures of these LPS components and their roles in colonization of the squid. WaaL ligates the O-antigen to the core of the LPS; thus, LPS from waaL mutants lacks O-antigen. Our results show that the V. fischeri waaL mutant has a motility defect, is significantly delayed in colonization, and is unable to compete with the wild-type strain in co-colonization assays. Comparative analyses of the LPS from the wild-type and waaL strains showed that the V. fischeri LPS has a single O-antigen repeat composed of yersiniose, 8-epi-legionaminic acid, and N-acetylfucosamine. In addition, the LPS from the waaL strain showed that the core structure consists of L-glycero-D-manno-heptose, D-glycero-D-manno-heptose, glucose, 3-deoxy-D-manno-octulosonic acid, N-acetylgalactosamine, 8-epi-legionaminic acid, phosphate, and phosphoethanolamine. These studies indicate that the unusual V. fischeri O-antigen sugars play a role in the early phases of bacterial colonization of the squid.
authors.affiliation: Buck Institute for Research on Aging, Novato, California 94945, USA.
authors.forename: Deborah M B
authors.initials: DM
authors.lastname: Post
authors.forename: Liping
authors.initials: L
authors.lastname: Yu
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Krasity
authors.forename: Biswa
authors.initials: B
authors.lastname: Choudhury
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Mandel
authors.forename: Caitlin A
authors.initials: CA
authors.lastname: Brennan
authors.forename: Edward G
authors.initials: EG
authors.lastname: Ruby
authors.forename: Margaret J
authors.initials: MJ
authors.lastname: McFall-Ngai
authors.forename: Bradford W
authors.initials: BW
authors.lastname: Gibson
authors.forename: Michael A
authors.initials: MA
authors.lastname: Apicella
mesh_terms: D048908:Aliivibrio fischeri / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D000825:Animal Structures / Q000382:microbiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002236:Carbohydrate Conformation; D050260:Carbohydrate Metabolism; D049832:Decapodiformes / Q000382:microbiology*; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D019081:O Antigens / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D019081:O Antigens; D008025:Ligases