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)

The Escherichia coli lac promoter mutation Pr115, an A X T to T X A transversion at +1 (the transcription initiation site of the lac wild-type and lac UV5 promoters), creates a new "-10 region"-like sequence starting at +1. We show that this mutation activates a new RNA polymerase binding site (P115) that overlaps with, and is shifted 12 base-pairs downstream from, the wild-type RNA polymerase binding site (P1). Nuclease S1 mapping studies and RNA polymerase protection experiments in vitro indicate that, in the absence of CAP-cAMP, this new site is used preferentially over the P1 site. In vivo, beta-galactosidase assays of the Pr115 mutation in combination with mutations of the P1 "-35 region" demonstrate that the P1 -35 region sequences are not involved in the interaction between RNA polymerase and P115 in the absence of CAP-cAMP; therefore P115 is an independent binding site. The presence of CAP-cAMP in vivo stimulates polymerase binding and initiation at P1, which serves to block polymerase from binding at P115.
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PMID:Lactose promoter mutation Pr115 activates an overlapping promoter within the lactose control region. 241 53

Transposition of the P[1ArB] vector was used to generate three mutations inducing sterility in homozygous males: ms(3)P50, ms(3)P122, and ms(3)P115 located within 67A4-B13, 92A2-14, and 75D regions on the polytene map. Staining for beta-galactosidase synthesized by P[1ArB] allowed us to study enhancer activity of these ms genes in the testicles. Their activity correlated to the presence of the YS arm but was little affected by the presence of YL arm of Y chromosome.
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PMID:[Y chromosomal factor controls transcription of autosomal fertility genes in Drosophila melanogaster males]. 989 5