Cloning and Bioinformatics Analysis of ZmASA2 Gene in Maize

Anthranilate synthase（AS） is a complex enzyme that catalyzes the synthesis of tryptophan in plant cells, consisting of α subunits and β subunits. In this study, a cDNA fragment encoding α subunit homologous gene of anthranilic acid synthase was cloned from corn B73 by RT-PCR technique, named ZmASA2. Amino acid sequence analysis showed that the total length of the cDNA fragment was 1 731 bp, and it was predicted to code a polypeptide containing 577 amino acids, with a molecular weight of about 64.48 kD and a theoretical isoelectric point of 6.64. Bioinformatics analysis showed that ZmASA2 was a hydrophilic protein located in the cytoplasm, and its secondary structure was mainly α helix. Phylogenetic analysis showed that ZmASA2 protein was the closest phylogenetic relation to AS of Miscanthus lutarioriparius and sorghum. The results of qRT-PCR showed that the expression of ZmASA2 was the highest at 30 days after pollination, followed by the stem.