Identification of a Conserved Histidine As Being Critical for the Catalytic Mechanism and Functional Switching of the Multifunctional Proline Utilization A Protein.

ABSTRACT: Proline utilization A from Escherichia coli (EcPutA) is a multifunctional flavoenzyme that oxidizes proline to glutamate through proline dehydrogenase (PRODH) and Δ¹-pyrroline-5-carboxylate dehydrogenase (P5CDH) activities, while also switching roles as a DNA-bound transcriptional repressor and a membrane-bound catabolic enzyme. This phenomenon, termed functional switching, occurs through a redox-mediated mechanism in which flavin reduction triggers a conformational change that increases EcPutA membrane binding affinity. Structural studies have shown that reduction of the FAD cofactor causes the ribityl moiety to undergo a crankshaft motion, indicating that the orientation of the ribityl chain is a key element of PutA functional switching. Here, we test the role of a conserved h

SUBMITTER: Moxley MA 

PROVIDER: S-EPMC5663281 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature