Characterization of a new endoglucanase from Erwinia chrysanthemi

The structural gene coding for a new endo-beta-1,4-glucanase of Erwinia chrysanthemi strain 3665, previously identified in a cosmid library, was subcloned into pUC18. The gene is expressed from a 1.9 X 10(3)-base-pair insert and its direction of transcription was determined. The properties of the gene product purified from cell-free extracts of Escherichia coli have been studied. The purified protein has an endoglucanase activity but is significantly different from the major endoglucanase Z secreted by E. chrysanthemi strain 3665. The new enzyme was designated as endoglucanase Y and the related gene celY. In E. coli, most of the endoglucanase activity was found in the periplasmic space.