In silico cloning and bioinformatics analysis of polyphenol oxidase gene coding sequence of banana

The banana polyphenol oxidase (PPO) gene coding sequence (CDS) was cloned in silico based on the EST sequences from Unigene of NCBI. Some characters of the protein encoded by PPO gene CDS were analyzed and predicted by the tools of bioinformatics in the following aspects, including the composition of amino acid sequence, hydrophobicity or hydrophilicity, secondary and tertiary structure of protein and function. Results showed that the coding sequence of banana PPO was 1 602 bp, containing a 1 602 bp ORF which encodes 533 AA. Banana PPO CDS contains two typical PPO domain and one PPO KFDV tyrosinase domain. It was highly conservative compared with PPO from several different plant species in sequence compositon, advanced structure and activity sites.