Capsular polysaccharides (CPSs) are protective structures on the surfaces of many Gram-negative bacteria. wcbI is one of several genes in the CPS biosynthetic cluster whose deletion leads to significant attenuation of the pathogen. Structural analysis and biophysical assays suggest that WcbI functions as an acetyltransferase enzyme but it requires another functional module to carry out this function. WcbI adopts a predominantly helical fold where the N-terminal 100 amino acids form a ligand-binding domain and binds tightly to coenzyme A and its derivative acetyl-CoA [1].

1: Structural insights into WcbI, a novel polysaccharide-biosynthesis enzyme. Vivoli M, Ayres E, Beaumont E, Isupov MN, Harmer NJ; IUCrJ. 2013;1:28-38. PMID:25075317