This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hall, B G
Right arrow Articles by Reeve, E C
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hall, B G
Right arrow Articles by Reeve, E C

 Previous Article  |  Next Article 

J Bacteriol. 1977 October; 132(1): 219-223

A third beta-galactosidase in a strain of Klebsiella that possesses two lac genes.

B G Hall and E C Reeve

ABSTRACT

Klebsiella strain RE1544 contains two lac operons, one on the chromosome and one on a lac plasmid. A mutant of RE1544, in which the lacZ genes of both operons produce no active enzyme, was found to synthesize a beta-galactosidase that hydrolyzes ortho-nitrophenyl-beta-D-galactopyranoside but not lactose. Synthesis of this beta-galactosidase (BGase-III) is induced by lactose but not by isopropyl-1-thio-beta-D-galactopyranoside or methyl-beta-D-thiogalactopyranoside. In both the regulation of synthesis and substrate specificity, BGase-III strongly resembles the ebg0 enzyme of Escherichia coli. Nevertheless, by the criteria of immunological cross-reactivity and subunit molecular weight, BGase-III is not related to the ebg0 enzyme.


J Bacteriol. 1977 October; 132(1): 219-223