Cas1p protein of Cryptococcus neoformans is required for the synthesis of O-acetylated glucuronoxylomannans, a consitutent of the capsule, and is critical for its virulence [1]. The multi TM domain of the Cas1p was unified with the 10 TM Sugar Acyltransferase superfamily [2]. This superfamily is comprised of members from the OatA, MdoC, OpgC, NolL and GumG families in addition to the Cas1p family [2]. The Cas1p protein has a N terminal PC-Esterase domain with the opposing Acyl esterase activity [2].

1: Cas1p is a membrane protein necessary for the O-acetylation of the Cryptococcus neoformans capsular polysaccharide. Janbon G, Himmelreich U, Moyrand F, Improvisi L, Dromer F; Mol Microbiol 2001;42:453-467. PMID:11703667

2: Novel eukaryotic enzymes modifying cell-surface biopolymers. Anantharaman V, Aravind L; Biol Direct. 2010;5:1. PMID:20056006