Cloning Cyclophilin cDNA Gene From Camellia Oleifera Abel

Camellia oleifera Abel (Teaoil Camellia) is a most important woody plant for edible oil production in China. Its oil possesses higher nutrient and medicinal values. Based on the cDNA library generated from mature seeds of ‘Yanggulao No. 1’, a full-length cDNA sequence of a gene, which consisted of 975 base pair (bp) and an open reading frame (ORF) of 621bp gene, was cloned. The gene encoded a protein (id: ACJ06541, predicted Mr of 22.24 kDa) of 207 amino acids. The gene was identified as cyclophilin gene because its nucleotied sequence shared the similarity of 96% (843/877) with that of Camellia sinensis cyclophilin. The putative protein possesses peptidyl-prolyl cis-trans isomerase (PPIase,EC 5.2.18.) activity and belongs to CyPB protein. Homology analysis indicated that its putative amino acid sequences shared high identity with those of other higher plant CyPs (e.g., 86% and 82% identity of those of Nicotiana tabacum cyclophilin-like protein and Arabidopsis thaliana cyclophilin protein). It also shows nearly 100% conservativeness in the four residues (Arg-96, Phe-101, His-167 and Tyr-162) of binding cyclosporn A (CsA) and catalysis. Prediction of structure showed that it mainly contains an N-terminal signal sequence, beta sheet accompanying with alpha helixes, beta turns and numerous random coils. The protein possesses an array of enzyme-binding sites, cyclophilin-type peptidyl-prolyl cis-trans isomerase signature, and a unique seven amino acid sequence KSGKPLH in numerous plant cyclophilins. The gene was submitted to GenBank (GenBank access number: FJ377540) and was termed as co-cyp1 gene. The gene expression during the peak of lipid biosynthesis might protect cell against reactive oxygen species (ROS) damage. Therefore, it may be crucial during both development and stress responsiveness.