Download MendeleyADP-ribosyl cyclase; crystal structures reveal a covalent intermediate.
Love, M.L., Szebenyi, D.M., Kriksunov, I.A., Thiel, D.J., Munshi, C., Graeff, R., Lee, H.C., Hao, Q.(2004) Structure 12: 477-486
- PubMed: 15016363
- DOI: https://doi.org/10.1016/j.str.2004.02.006
- Primary Citation of Related Structures:
1R0S, 1R12, 1R15, 1R16 - PubMed Abstract:
ADP-ribosyl cyclase catalyzes the elimination of nicotinamide from NAD and cyclization to cADPR, a known second messenger in cellular calcium signaling pathways. We have determined to 2.0 A resolution the structure of Aplysia cyclase with ribose-5-phosphate bound covalently at C3' and with the base exchange substrate (BES), pyridylcarbinol, bound to the active site. In addition, further refinement at 2.4 A resolution of the structure of nicotinamide-bound cyclase, which was previously reported, reveals that ribose-5-phosphate is also covalently bound in this structure, and a second nicotinamide site was identified. The structures of native and mutant Glu179Ala cyclase were also solved to 1.7 and 2.0 A respectively. It is proposed that the second nicotinamide site serves to promote cyclization by clearing the active site of the nicotinamide byproduct. Moreover, a ribosylation mechanism can be proposed in which the cyclization reaction proceeds through a covalently bound intermediate.
Organizational Affiliation:
Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853 USA.
