Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

None of the Agrobacterium tumefaciens and A. rubi strains tested produces detectable amounts of beta-galactosidase although they are capable of utilizing lactose as sole source of carbon. This opportunity was taken to investigate the expression of lac transposon Tn951 (Cornelis et al. 1978) in Agrobacterium with the ultimate goal of using this system to investigate alien gene expression. When the transposon was introduced with the help of a broad-host range plasmid, RP1, the transconjugants produced significant quantities of beta-galactosidase which was inducible by isopropyl-beta-D-thiogalactopyranoside. Tn951 was capable of restoring the Lac+ phenotype to an A. tumefaciens mutant not capable of using lactose. Cellobiose, a known inducer of aldohexopyranoside: cytochrome c oxidoreductase (which regulates the characteristic 3-ketolactose production in Agrobacterium; van Beeumen and De Ley (1968), had no effect on beta-galactosidase activity.
 ...
PMID:Studies on Tn951 (lac+) expression in Agrobacterium. 632 25

Herman, Alberta (University of Wisconsin, Madison) and Harlyn Halvorson. Identification of the structural gene for beta-glucosidase in Saccharomyces lactis. J. Bacteriol. 85:895-900. 1963.-Three allelic forms (B(h, m, l)) of the structural gene for beta-glucosidase have been identified in the yeast Saccharomyces lactis. Evidence that these are structural gene alleles includes the independent expression of the alleles in homozygous and heterozygous diploids and differences in the specificity and in the physical properties of the enzyme produced in response to the various allelic mutations. Two factors, one controlling production of the pulcherrimin-like pigment, the other beta-galactosidase activity, are linked to the B locus. The beta-glucosidase in these strains hydrolyzes the chromogenic substrate, p-nitrophenyl-beta-d-glucoside, arbutin, salicin, and esculin. Cellobiose, on the other hand, is hydrolyzed by another enzyme.
 ...
PMID:IDENTIFICATION OF THE STRUCTURAL GENE FOR BETA-GLUCOSIDASE IN SACCHAROMYCES LACTIS. 1404 60