Cloning and Sequence Analysis of AcPME Gene in Onion

doi:10.14083/j.issn.1001-4942.2017.06.002

Abstract：The sequence of AcPME gene was obtained through rapid amplification of cDNA ends (RACE) based on the sample of onion flower bud.The GenBank accession number was JF913196.1.The AcPME genomic DNA consisted of 2 786 bases with 4 exons and 3 introns.The cDNA length was 2 228 bp with a 2 001 bp ORF and encoded 666 amino acids.The bioinformatic analysis showed that the AcPME protein consisted of a signal peptide and transmembrane domain (SP/TM), a PMEI structural domain and a PME structural domain, which belonged to type I with a long N terminal PRO-region in the PME families.The amino acid homologous alignment and phylogenetic tree analysis exhibited that there were higher identities between AcPME and PME of homologous monocotyledons such as rice, maize and sorghum.The three-dimensional structure map showed AcPME protein had an obvious shallow cleft, 4 amino acid residues (T423, Q453, R565 and W567) binding to substrate and 2 residues (D476 and D497) involved in catalysis.The research laid a foundation for the biological functions of AcPME protein and the interactions between PMEI and PME domains.