Evidence that the C-terminal domain of a type B PutA protein contributes to aldehyde dehydrogenase activity and substrate channeling.

ABSTRACT: Proline utilization A (PutA) is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate. Structures of type A PutAs have revealed the catalytic core consisting of proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH) modules connected by a substrate-channeling tunnel. Type B PutAs also have a C-terminal domain of unknown function (CTDUF) that is absent in type A PutAs. Small-angle X-ray scattering (SAXS), mutagenesis, and kinetics are used to determine the contributions of this domain to PutA structure and function. The 1127-residue Rhodobacter capsulatus PutA (RcPutA) is used as a representative CTDUF-containing type B PutA. The reaction progress curve for the coupled PRODH-P5CDH activity of RcPutA does not exhibit a time lag, implying a s

SUBMITTER: Luo M 

PROVIDER: S-EPMC4159212 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature