Dynamic elements govern the catalytic activity of CapE, a capsular polysaccharide-synthesizing enzyme from Staphylococcus aureus

CapE is an essential enzyme for the synthesis of capsular polysaccharide (CP) of pathogenic strains of Staphylococcus aureus . Herein we demonstrate that CapE is a 5‐inverting 4,6‐dehydratase enzyme. However, in the absence of downstream enzymes, CapE catalyzes an additional reaction (5‐back‐epimerization) affording a by‐product under thermodynamic control. Single‐crystal X‐ray crystallography was employed to identify the structure of the...