Sugar nucleotide transferases in lipopolysaccharide biosynthesis

The cell wall lipopolysaccharide (LPS) of 0111 is a complex polymer which contains fatty acids, phosphorus, hexosamine, 3-deoxy-octulosonate (KDO) (Heath and Ghalambor, 1963), heptose, glucose, galactose and colitose (3,6 dideoxy-L-xylohexose). A mutant of this organism, J-5 (Heath and Elbein, 1962), lacks the enzyme UDP-galactose-4-epimerase. When the organism is grown in the absence of galactose, an incomplete LPS is formed which lacks galactose and colitose and contains reduced amounts of glucose and N-acetyl glucosamine. This paper presents evidence for the sequential enzymatic transfer of galactose, glucose, N-acetyl glucosamine and colitose (from their respective nucleotide derivatives) to the deficient LPS of J-5. Further, evidence is presented indicating that the transfer of KDO, from cytidine monophosphate-KDO(CMP-KDO) is catalyzed by crude extracts from either the wild-type organism or the mutant; the acceptor for this transferase is a fragment of LPS obtained by chemical degradation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32107/1/0000157.pd