Structural and functional analysis of KfiA, a UDP-GlcNAc transferase involved in Escherichia coli K5 heparosan biosynthesis.
Heparosan is a linear glycosaminoglycan-related polysaccharide produced as the capsular polysaccharide of Escherichia coli K5. Its biosynthesis requires alternating transfer of N-acetylglucosamine and glucuronic acid by the glycosyltransferases KfiA and KfiC, respectively, but the structural basis of KfiA function has...