Orotidine 5'-Monophosphate Decarboxylase: The Operation of Active Site Chains Within and Across Protein Subunits.

ABSTRACT: The D37 and T100' side chains of orotidine 5'-monophosphate decarboxylase (OMPDC) interact with the C-3' and C-2' ribosyl hydroxyl groups, respectively, of the bound substrate. We compare the intra-subunit interactions of D37 with the inter-subunit interactions of T100' by determining the effects of the D37G, D37A, T100'G, and T100'A substitutions on the following: (a) k_cat and k_cat/K_m values for the OMPDC-catalyzed decarboxylations of OMP and 5-fluoroorotidine 5'-monophosphate (FOMP) and (b) the stability of dimeric OMPDC relative to the monomer. The D37G and T100'A substitutions resulted in 2 kcal mol^-1 increases in ΔG^† for k_cat/K_m for the decarboxylation of OMP, while t

SUBMITTER: Brandao TAS 

PROVIDER: S-EPMC7476526 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature