Molecular organization of exopolysaccharide (EPS) encoding genes on the lactococcal bacteriophage adsorption blocking plasmid, pCI658.
The lactococcal plasmid pCI658 (58 kb) isolated from Lactococcus lactis ssp. cremoris HO2 encodes the production of a hydrophilic exopolysaccharide (EPS) which consists primarily of galactose and glucuronic acid and which interferes with adsorption of phages ø712 and øc2 to cell surface receptors. Examination of the nucleotide sequence of a 21.8-kb region of the plasmid revealed a large genetic cluster consisting of at least 23 putative EPS biosynthetic determinants in addition to the presence of insertion sequences at the 5(') and 3(') ends. According to homology searches, the genes were organized in specific regions involved in regulation, synthesis and export of the EPS. The predicted products of individual genes exhibited significant homology to exopolysaccharide, capsular polysaccharide (CPS), and lipopolysaccharide (LPS) gene products from a variety of Gram positive and Gram negative bacteria. Evidence of a gene encoding UDP-glucose dehydrogenase is also presented and this is the first description of such a gene in Lactococcus.
Department of Microbiology, University College, Cork, Ireland.
Amanda
A
Forde
Gerald F
GF
Fitzgerald
D000327:Adsorption; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001435:Bacteriophages / Q000502:physiology*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002772:Cholera Toxin / Q000235:genetics; D003001:Cloning, Molecular; D023061:Gene Order; D017045:Lactococcus / Q000235:genetics* / Q000821:virology; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009876:Operon; D011135:Polysaccharides, Bacterial / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics
D001426:Bacterial Proteins; D002352:Carrier Proteins; C406586:EpsD protein, Vibrio cholerae; C079398:EpsE protein, Vibrio cholerae; D008565:Membrane Proteins; D011135:Polysaccharides, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors; C087016:epsR protein, Ralstonia solanacearum; D002772:Cholera Toxin