The localization of KpsC, S and T, and KfiA, C and D proteins involved in the biosynthesis of the Escherichia coli K5 capsular polysaccharide: evidence for a membrane-bound complex.

Biosynthesis of the Escherichia coli K5 polysaccharide requires the KfiA, KfiB, KfiC and KfiD proteins. The subsequent transport of the polysaccharide onto the cell surface requires the KpsC, KpsD, KpsE, KpsM, KpsS and KpsT proteins, which are conserved between different group II capsular polysaccharides. The KfiA and KfiC, together with the KpsC, KpsS and KpsT proteins, were purified and polyclonal antisera to each protein generated.