Evolution of plant δ(1)-pyrroline-5-carboxylate reductases from phylogenetic and structural perspectives.
Proline plays a crucial role in cell growth and stress responses, and its accumulation is essential for the tolerance of adverse environmental conditions in plants. Two routes are used to biosynthesize proline in plants. The main route uses glutamate as a precursor, while in the other route proline is derived from ornithine. The terminal step of both pathways, the conversion of δ(1)-pyrroline-5-carboxylate (P5C) to L-proline, is catalyzed by P5C reductase (P5CR) using NADH or NADPH as a cofactor. Since P5CRs are important housekeeping enzymes, they are conserved across all domains of life and appear to be relatively unaffected throughout evolution. However, global analysis of these enzymes unveiled significant functional diversity in the preference for cofactors (NADPH vs. NADH), variation in metal dependence and the differences in the oligomeric state. In our study we investigated evolutionary patterns through phylogenetic and structural analysis of P5CR representatives from all kingdoms of life, with emphasis on the plant species. We also attempted to correlate local sequence/structure variation among the functionally and structurally characterized members of the family.
Department of Life Science and Biotechnology, University of Ferrara Ferrara, Italy.
Giuseppe
G
Forlani
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda MD, USA.
Kira S
KS
Makarova
Synchrotron Radiation Research Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Argonne National Laboratory, Argonne IL, USA.
Milosz
M
Ruszkowski
Department of Life Science and Biotechnology, University of Ferrara Ferrara, Italy.
Michele
M
Bertazzini
The Bioscience Division, Argonne National Laboratory, Argonne IL, USA.
Boguslaw
B
Nocek
3-D structures of P5CRs; P5C reductase; cofactor preference; oligomer structure prediction; phylogenetic analysis