Structural Determinants for Substrate Selectivity in Guanine Deaminase Enzymes of the Amidohydrolase Superfamily.

ABSTRACT: Guanine deaminase is a metabolic enzyme, found in all forms of life, which catalyzes the conversion of guanine to xanthine. Despite the availability of several crystal structures, the molecular determinants of substrate orientation and mechanism remain to be elucidated for the amidohydrolase family of guanine deaminase enzymes. Here, we report the crystal structures of Escherichia coli and Saccharomyces cerevisiae guanine deaminase enzymes (EcGuaD and Gud1, respectively), both members of the amidohydrolase superfamily. EcGuaD and Gud1 retain the overall TIM barrel tertiary structure conserved among amidohydrolase enzymes. Both proteins also possess a single zinc cation with trigonal bipyrimidal coordination geometry within their active sites. We also determined a liganded str

SUBMITTER: Shek R 

PROVIDER: S-EPMC6677139 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature