Kinetic and structural characterization of carboxyspermidine dehydrogenase of polyamine biosynthesis.

ABSTRACT: Polyamines are positively charged alkylamines ubiquitous among eukaryotes, prokaryotes, and archaea. Humans obtain polyamines through dietary intake, metabolic production, or uptake of polyamines made by gut microbes. The polyamine biosynthetic pathway used by most gut microbes differs from that used by human cells. This alternative pathway employs carboxyspermidine dehydrogenase (CASDH), an enzyme with limited characterization. Here, we solved a 1.94 Å X-ray crystal structure of Bacteroides fragilis CASDH by molecular replacement. BfCASDH is composed of three domains with a fold similar to saccharopine dehydrogenase but with a distinct active site arrangement. Using steady-state methods, we determined k_cat and k_cat/K_m for BfCASDH and Clostridium leptum CAS

SUBMITTER: Lee DF 

PROVIDER: S-EPMC10413350 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature