Structural basis for catalysis in a CDP-alcohol phosphotransferase.

Giuliano Sciara (1, 2) , Oliver B Clarke (3) , David Tomasek (2) , Brian Kloss (4) , Shantelle Tabuso (4) , Rushelle Byfield (2) , Raphael Cohn (2) , Surajit Banerjee (5) , Kanagalaghatta R Rajashankar (5) , Vesna Slavkovic (6) , Joseph H Graziano (6) , Lawrence Shapiro (3) , Filippo Mancia (2)

1 BBF - Biodiversité et Biotechnologie Fongiques
2 Department of Physiology and Cellular Biophysics
3 DBMB - Department of Biochemistry and Molecular Biophysics
4 NYSBC - New York Structural Biology Center
5 Department of Chemistry and Chemical Biology
6 Department of Environmental Health Sciences, Mailman School of Public Health

The CDP-alcohol phosphotransferase (CDP-AP) family of integral membrane enzymes catalyses the transfer of a substituted phosphate group from a CDP-linked donor to an alcohol acceptor. This is an essential reaction for phospholipid biosynthesis across all kingdoms of life, and it is catalysed solely by CDP-APs. Here we report the 2.0 Å resolution crystal structure of a representative CDP-AP from Archaeoglobus fulgidus. The enzyme (AF2299) is a homodimer, with each protomer consisting of six transmembrane helices and an N-terminal cytosolic domain. A polar cavity within the membrane accommodates the active site, lined with the residues from an absolutely conserved CDP-AP signature motif (D(1)xxD(2)G(1)xxAR...G(2)xxxD(3)xxxD(4)). Structures in the apo, CMP-bound, CDP-bound and CDP-glycerol-bound states define functional roles for each of these eight conserved residues and allow us to propose a sequential, base-catalysed mechanism universal for CDP-APs, in which the fourth aspartate (D4) acts as the catalytic base.

Mots clés: phosphotransférase system; phospholipide membranaire; escherichia coli

Domaines: Sciences du Vivant [q-bio]

Giuliano Sciara, Oliver B Clarke, David Tomasek, Brian Kloss, Shantelle Tabuso, et al.. Structural basis for catalysis in a CDP-alcohol phosphotransferase.. Nature Communications, 2014, 5, pp.4068. ⟨10.1038/ncomms5068⟩. ⟨hal-01594683⟩