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Molecular cloning and characterization of the beta‐amylase gene from Bacillus circulans
Author(s) -
Siggens K. W.
Publication year - 1987
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1987.tb00531.x
Subject(s) - bacillus circulans , biology , open reading frame , gene , molecular cloning , microbiology and biotechnology , amylase , enzyme , biochemistry , structural gene , escherichia coli , peptide sequence
Summary A gene encoding the β‐amylase of Bacillus circulans was isolated from a lambda library and sequenced. The structural gene consists of a 1725 bp open reading frame encoding a polypeptide with a predicted molecular wt of 62830 Daltons. Two active forms of the enzyme were found when the gene was expressed In E. coli. The larger 60 kD form was approximately 3 kD larger than the mature β‐amylase secreted from B. circulans , suggesting that processing of this protein is different between the two species. The smaller 49 kD form is also present at a low level in B. circulans and may result from proteolytic cleavage. The enzyme has a temperature optimum of 50°C. Two other genes, one encoding an α‐amylase and one a pullulanase, were also isolated from the lambda library.