Naturally occurring mutations exist at the functionally important motifs of piperine synthase genes among Piper species
摘要
Piperine synthase, one of the key enzymes involved in the piperine biosynthetic pathway belong to the family of BAHD acyltransferases. In the present study, the gene sequence encoding BAHD acyltransferase domain of piperine synthase gene was sequenced from two Piper nigrum cultivars Panniyur-1 and Panniyur-4; and from its wild species Piper colubrinum. The sequence analysis revealed distinct variation in the structurally important motif among two species, and HAIAD and HVIAD motifs were identified from P. nigrum and P. colubrinum. The comparative genome-wide analysis of piperine synthase homolog of other Piper species such as P. betel, P. longum and P. retrofractum showed 92–93 percent similarity to that of P. nigrum sequence. Meanwhile BAHD acyltransferase domain of P. colubrinum and P. methysticum showed considerable sequence variation from that of P. nigrum. The Alanine to Valine substitution in HXXXD motif was also identified from the BAHD acyl transferase domain of P. longum, P. betel, P. retrofractum and P. methysticum through the genome-wide analysis. The binding pocket and binding volume of the BAHD-acyl transferase of piperine synthase from P. nigrum and P. longum were predicted as low compared to other species. The phylogenetic analysis also revealed the clustering of P. nigrum, P. betel and P. longum, while P. colubrinum and P. methystichum as separate groups. The natural mutation that affects the substitution of amino acids can lead novel function and activity, and further contributes to identification of novel molecular targets.