RT Journal Article SR Electronic T1 Structure of the human heterotetrameric cis-prenyltransferase complex JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.06.02.095570 DO 10.1101/2020.06.02.095570 A1 Bar-El, Michal Lisnyansky A1 Vankova, Pavla A1 Man, Petr A1 Haitin, Yoni A1 Giladi, Moshe YR 2020 UL http://biorxiv.org/content/early/2020/06/02/2020.06.02.095570.abstract AB The human cis-prenyltransferase (hcis-PT) is an enzymatic complex essential for protein N-glycosylation. Synthesizing the precursor of the glycosyl carrier dolichol-phosphate, we reveal here that hcis-PT exhibits a novel heterotetrameric assembly in solution, composed of two catalytic dehydrodolichyl diphosphate synthase (DHDDS) and two inactive Nogo-B receptor (NgBR) subunits. The 2.3 Å crystal structure of the complex exposes a dimer-of-heterodimers arrangement, with DHDDS C-termini serving as homotypic assembly domains. Furthermore, the structure elucidates the molecular details associated with substrate binding, catalysis, and product length determination. Importantly, the distal C-terminus of NgBR transverses across the heterodimeric interface, directly participating in substrate binding and underlying the allosteric communication between the subunits. Finally, mapping disease-associated hcis-PT mutations involved in blindness, neurological and glycosylation disorders onto the structure reveals their clustering around the active site. Together, our structure of the hcis-PT complex unveils the dolichol synthesis mechanism and its perturbation in disease.Competing Interest StatementThe authors have declared no competing interest.