First evidence for substrate channeling between proline catabolic enzymes: a validation of domain fusion analysis for predicting protein-protein interactions.

ABSTRACT: Proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate (P5C) dehydrogenase (P5CDH) catalyze the four-electron oxidation of proline to glutamate via the intermediates P5C and l-glutamate-γ-semialdehyde (GSA). In Gram-negative bacteria, PRODH and P5CDH are fused together in the bifunctional enzyme proline utilization A (PutA) whereas in other organisms PRODH and P5CDH are expressed as separate monofunctional enzymes. Substrate channeling has previously been shown for bifunctional PutAs, but whether the monofunctional enzymes utilize an analogous channeling mechanism has not been examined. Here, we report the first evidence of substrate channeling in a PRODH-P5CDH two-enzyme pair. Kinetic data for the coupled reaction of PRODH and P5CDH from Thermus thermophilus are consistent with a

SUBMITTER: Sanyal N 

PROVIDER: S-EPMC4303673 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature