Streptococcus pneumoniae serotype 1 capsular polysaccharide (CPS type 1)

The Streptococcus pneumoniae serotype 1 capsular polysaccharide (CPS) is a key surface structure and major virulence factor that shields the bacterium from host phagocytosis and opsonophagocytic clearance. It is synthesized via a Wzx/Wzy-dependent pathway involving lipid-linked repeat units translocated across the membrane, polymerized, and covalently linked at the reducing end (often glucose) to peptidoglycan GlcNAc via a 1,6 glycosidic bond. Serotype 1 CPS initiation uniquely involves a teichoic acid biosynthesis glycosyltransferase. With 98 distinct serotypes recognized, protection by vaccines is strictly serotype-specific, targeting CPS to elicit protective antibodies. Genes in the cps1 locus (wzg to ugd) are highly conserved and can transfer to commensal streptococci like S. mitis.

Other names

serotype 1 CPSpneumococcal serotype 1 capsuletype 1 capsular polysaccharide

Induces serotype-specific antibodies for opsonophagocytic killing