Genetic and chemical characterization of a mutant that disrupts synthesis of the lipopolysaccharide core tetrasaccharide in Rhizobium leguminosarum.
A 2-kb region that complements the Tn5-derived lipopolysaccharide (LPS) rough mutant Rhizobium leguminosarum RU301 was sequenced. Two open reading frames (ORFs) were identified. The first ORF (lpcA) is homologous to a family of bacterial sugar transferases involved in LPS core tetrasaccharide biosynthesis. ORF2 (lpcB), in which Tn5 transposed, has no significant homology to any DNA in the GenBank-EMBL databases. Chemical characterization of LPS produced by strain RU301 demonstrated that the 3-deoxy-D-manno-2-octulosonic acid (Kdo) residue which normally attaches the core tetrasaccharide to the O chain was missing, suggesting that IpcB may encode a CMP-Kdo:LPS Kdo transferase.
Allaway
D
D
School of Animal and Microbial Science, University of Reading, United Kingdom.
Jeyaretnam
B
B
Carlson
R W
RW
Poole
P S
PS
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004269:DNA, Bacterial; D006602:Hexosyltransferases / Q000235:genetics*; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009154:Mutation; D016961:Rhizobium leguminosarum / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D014166:Transferases / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008070:Lipopolysaccharides; D014166:Transferases; D006602:Hexosyltransferases; C102674:LpcA protein, Rhizobium leguminosarum; C019917:3-deoxy-D-manno-octulosonate transferase