UNIQUE PRIMARY STRUCTURE OF A THERMOSTABLE MULTIMETAL BETA-GALACTOSIDASE FROM SACCHAROPOLYSPORA-RECTIVIRGULA

The gene of the monomeric multimetal beta-galactosidase of Saccharapol yspora rectivirgula was cloned and sequenced. Although the enzyme coul d be assigned as a member of beta-galactasidases belonging to the glyc osyl hydrolase family 2, it has unusual structural features for beta-g alactosidase of this family; it contained a unique sequence which cons ists of approximately 200 amino acid residues with no similarity to kn own proteins. This 200-fesidue sequence exists as if it is inserted in to a sequence homologous to the active-site domain of the Escherichia coli lacZ enzyme. (C) 1998 Elsevier Science B.V. All rights reserved.