Visualization of covalent intermediates and conformational states of proline utilization A by X-ray crystallography and molecular dynamics simulations.

ABSTRACT: The bifunctional enzyme proline utilization A (PutA) catalyzes the two-step oxidation of L-proline to L-glutamate using proline dehydrogenase (PRODH) and L-glutamate-γ-semialdehyde dehydrogenase (GSALDH) domains. The two active sites are 42 Å apart and connected by a buried tunnel that is hypothesized to channel the intermediates Δ¹-pyrroline-5-carboxylate (P5C) and/or L-glutamate-γ-semialdehyde (GSAL). Kinetic and conventional X-ray crystallography of PutA from Sinorhizobium meliloti (SmPutA) were used to capture high resolution (1.47-1.88 Å) structures of states along the catalytic cycle, including a novel FADH^--proline covalent adduct in the PRODH site, the intermediate P5C bound noncovalently in the reduced PRODH active site, the covalent acyl-enzyme intermediate

SUBMITTER: Buckley DP 

PROVIDER: S-EPMC12398946 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature