RT Journal Article SR Electronic T1 Purification of the mammalian NgBR/hCIT cis-prenyltransferase complex: Identification of a conserved carboxyterminal RxG motif crucial for enzymatic activity JF bioRxiv FD Cold Spring Harbor Laboratory SP 139675 DO 10.1101/139675 A1 Grabińska, Kariona A. A1 Edani, Ban H. A1 Park, Eon Joo A1 Kraehling, Jan R. A1 Sessa, William C. YR 2017 UL http://biorxiv.org/content/early/2017/05/18/139675.abstract AB Cis-Prenyltransferases (cisPTs) constitute a large family of enzymes conserved during evolution and present in all domains of life. In eukaryotes and archaea, cisPT is the first enzyme committed to the synthesis of dolichyl-phosphate (DolP). DolP is obligate lipid carrier in protein glycosylation reactions in mammals. The homodimeric bacterial enzyme, undecaprenyl diphosphate synthase (UPPS) generates 11 isoprene units and has been structurally and mechanistically characterized in great detail. Recently our group discovered that unlike UPPS, mammalian cisPT is a heteromer consisting of NgBR (NUS1) and hCIT (DHDDS) subunits and this composition has been confirmed in plants and fungal cisPTs. Here, we establish the first purification system for heteromeric cisPT and show that both NgBR and hCIT subunits function in catalysis and substrate binding. Finally, we identified a critical RxG sequence in the C-terminal tail of NgBR that is conserved and essential for enzyme activity across phyla.