Isolation and Characterization of An Aldo-Keto Reductase cDNA from Camellia Oleifera Seed

Camellia Oleifera is a kind of important plants in South China as the oil, containing above 90% unsaturated fatty acid, from its seeds has high nutrition value. In order to reveal the lipid biosynthesis in the seeds, the transcriptome and related genes expression profiling programmes for the seeds were constructed by Solexa technology. One of these genes encodes a protein similar to a superfamily of aldo-keto reductase with structurally and functionally related NADPH-dependent oxidoreductase was discovered by assembling and annotation, and it was named as Co-AKR. The full-length cDNA of Co-AKR was isolated with the RACE and RT-PCR methods in this work. Bioinformatic analysis indicated that the cDNA is 1194 bp in length, encoding 316 amino acids residues, the putative molecular weight is 35.07 kD and the pI is 6.55, and there are several conserved domains in the protein sequence aligned with other AKRs. The phylogenetic investigation displayed that the relationship among the same class AKR family was very close. Fifteen α-helices and five β-strands were detected in the second structure of Co-AKR and its theoretical 3D structure showed an active site between Leu22 and Lys266 after protein biological folding. The subcellular location prediction suggested that it could be mainly integrated with chloroplast.