Sequence Analysis and Heterologous Expression of Rhamnogalacturonan Lyase A Gene (AsrglA) from Shoyu Koji Mold, Aspergillus sojae KBN1340

Abstract

The rhamnogalacturonan lyase A gene, designated AsrglA, was isolated from a shoyu koji mold, Aspergillus sojae KBN1340, and characterized. The structural gene comprised 2,245 bp with 11 introns. The open reading frame encoded a 528-residue protein with a signal peptide of 20 residues. AsrglA shared a high degree of sequence identity with Aspergillus oryzae rhamnogalacturonate lyase A and Aspergillus flavus rhamnogalacturonase B. Utilizing the promoter of the A. oryzae taaG2 gene, AsRglA was successfully expressed in A. oryzae and secreted into the culture medium. AsRglA had a molecular mass of 55.0 kDa, a pH optimum of 4.5, and a temperature optimum of 50℃.