Enzyme Architecture: Erection of Active Orotidine 5'-Monophosphate Decarboxylase by Substrate-Induced Conformational Changes.

ABSTRACT: Orotidine 5'-monophosphate decarboxylase (OMPDC) catalyzes the decarboxylation of 5-fluoroorotate (FO) with k_cat/K_m = 1.4 × 10^-7 M^-1 s^-1. Combining this and related kinetic parameters shows that the 31 kcal/mol stabilization of the transition state for decarboxylation of OMP provided by OMPDC represents the sum of 11.8 and 10.6 kcal/mol stabilization by the substrate phosphodianion and the ribosyl ring, respectively, and an 8.6 kcal/mol stabilization from the orotate ring. The transition state for OMPDC-catalyzed decarboxylation of FO is stabilized by 5.2, 7.2, and 9.0 kcal/mol, respectively, by 1.0 M phosphite dianion, d-glycerol 3-phosphate and d-erythritol 4-phosphate. The stabilization is due to the utilization of binding interacti

SUBMITTER: Reyes AC 

PROVIDER: S-EPMC5720041 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature