Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The first two genes pcbAB and pcbC of the penicillin biosynthesis pathway are expressed from a 1.01-kilobase bidirectional promoter region. A series of sequential deletions were made in the pcbAB promoter region, and the constructions with the modified promoters coupled to the lacZ reporter gene were introduced as single copies at the pyrG locus in Penicillium chrysogenum npe10. Three regions, boxes A, B, and C, produced a significant decrease in expression of the reporter gene when deleted. Protein-DNA complexes were observed by using the electrophoretic mobility shift assay with boxes A and B (complexes AG1, BG1, BG2, and BL1) but not with box C. Uracil interference assay showed that a protein in P. chrysogenum cell extracts interacts with the thymines in a palindromic heptanucleotide TTAGTAA. Point mutations and deletion of the entire TTAGTAA sequence supported the involvement of this sequence in the binding of a transcriptional activator named penicillin transcriptional activator 1 (PTA1). In vivo studies using constructions carrying point mutations in the TTAGTAA sequence (or a deletion of the complete heptanucleotide) confirmed that this intact sequence is required for high level expression of the pcbAB gene. The TTAGTAA sequence resembles the target sequence of BAS2 (PHO2), a factor required for expression of several genes in yeasts.
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PMID:A novel heptameric sequence (TTAGTAA) is the binding site for a protein required for high level expression of pcbAB, the first gene of the penicillin biosynthesis in Penicillium chrysogenum. 1064 95

AdpA, belonging to the AraC/XylS family, is the key transcriptional activator for a number of genes of various functions in the A-factor regulatory cascade in Streptomyces griseus. It consists of a ThiJ/PfpI/DJ-1-like dimerization domain at its N-terminal portion and a DNA-binding domain with two helix-turn-helix motifs at its C-terminal portion, representing a large subgroup of the AraC/XylS family. Uracil interference assay and missing T and GA interference assays on several AdpA binding sites, followed by gel mobility shift assays on systematically mutated binding sites, revealed a consensus AdpA-binding sequence, 5'-TGGCSNGWWY-3' (S: G or C; W: A or T; Y: T or C; N: any nucleotide). A dimer of AdpA bound a site including the two consensus sequences, with a space of 13-14 bp, as an inverted repeat (type I) at various positions, for example more than 200 bp upstream (-200) and 25 bp downstream (+25) from the transcriptional start point of the target gene. In addition, AdpA also bound a site including the consensus sequence in a single copy (type II) at positions, in most cases, from -40 to -50 and from -50 to -60. For transcriptional activation, some genes required simultaneous binding of a dimer of AdpA to type I and II sites, but others required only a single type I or type II site. AdpA bound mutated type I sites with various distances between the two consensus sequences with significant affinities, although the optimal distances for AdpA to bind were 13-14 bp and 2 bp. The DNA-binding domain is therefore connected to the ThiJ/PfpI/DJ-1-like dimerization domain with a flexible linker. The DNA-binding specificity of AdpA in conjunction with that of other AraC/XylS family members is discussed.
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PMID:DNA-binding specificity of AdpA, a transcriptional activator in the A-factor regulatory cascade in Streptomyces griseus. 1522 17