Abstract: In order to enrich basic data in Paeonia lactiflora CHI gene, the CDS region of Paeonia lactiflora CHI gene was cloned by RACE technology, further codon usage was analyzed by EMBOSS software, then the structure and function of CHI protein was predicted by bioinformatics software and online databases.Results indicated that, the 898 bp full-length cDNA of CHI of Paeonia lactiflora (GenBank No.:JN119872)was obtained.Paeonia lactiflora CHI gene has certain preference of codon usage with the terminal base A or U.There were twenty-eight biased codons(RSCU > 1), whose biased strongly codons were UUG, UGU, CAU, AGA, AGG and CGG(RSCU≥2).In codon usage frequency, the differences between CHI gene and Saccharomyces, E.coli genomes were more than Arabidopsis genome.CHI was non-transmembrane and hydrophilic protein with no signal peptide, which located mostly in cytoplasm(45.0%) and microbody(42.5%) by the result of subcellular level prediction and does not belong to the secretory protein.CHI protein had no glycosylation sites and fourteen phosphorylation sites, including a PKC kinase located in 20th amino acid.Additionally, it had one conservative domain named chalcone.The secondary structure of CHI protein contained 39% α-helices, 20% extended strand, 13% β-turn and 27% random coil.Tertiary structure presented an inversion bouquet by beta sandwich folding.In this study, we found one conservative domain responsible for catalytic activity of isomerase and an specific protein kinases PKC site, which will provide advantageous basic data for further studying CHI gene function.Moreover, the eukaryotic Saccharomyces expression systems may be more suitable for the expression of CHI gene.

Key words: Paeonia lactiflora, CHI gene, Codon usage bias, Protein structure and function

CLC Number: 

• Q78

• S682.03