   1.5.1.B5 | L-proline + NAD+ = DELTA1-pyrroline-2-carboxylate + NADH + H+ |
catalytic mechanism, overview. The hydride ion is transferred from the C4 atom of NADH to the C2 atom of Pyr2C, causing electron transfer to the vicinal N atom of Pyr2C, which is now capable of accepting the proton donated by the guanidine group of Arg43. The product L-proline forms a hydrogen bond to the carbonyl O atom of Val301, which stabilizes formation of the product prior to its release. Lys71 and Arg114 are highly conserved and are involved in substrate binding through their interaction with the substrate carboxyl group. But the NH2 group of the guanidine of Arg43 engages in a hydrogen bond to the close carbonyl O atom of Val301 and to the distant N atom of the substrate, the putative proton acceptor of the catalytic reaction |
-, 763843 |
