Disease relevance of TRP5

• DNA sequences flanking an E. coli insertion element IS2 in a cloned yeast TRP5 gene [1].
• Nucleotide sequence of the genes for tryptophan synthase in Pseudomonas aeruginosa [2].

High impact information on TRP5

• Expression of the yeast tryptophan synthetase activity from the cloned yeast gene (trp5) is relatively inefficient in E. coli, as measured by growth rates of trpAB/pYe(trp5)1 strains on minimal media lacking tryptophan and by enzyme assays [3].
• Plasmid DNA [pYe(trp5)2] from one of these variants was shown to contain a DNA insertion (1.3 kilobase pairs) in the cloned yeast DNA segment in relatively close proximity to the trp5 gene [3].
• Control of expression of a cloned yeast (Saccharomyces cerevisiae) gene (trp5) by a bacterial insertion element (IS2) [3].
• The peak reversion frequency for lys5 is somewhat later, while the peaks for tyr3 and trp5 occur near the end of DNA replication [4].
• The R388 plasmid-encoded drug-resistant type II dihydrofolate reductase gene (R . dhfr) was expressed in Saccharomyces cerevisiae by fusing the R . dhfr coding sequence to the yeast TRP5 promoter [5].

Chemical compound and disease context of TRP5

• Accordingly, poor expression of the first Trp-enzyme anthranilate synthase and the last enzyme tryptophan synthase was found, whereas the other three genes were moderately well expressed in E. coli [6].
• Active site cysteine, histidine, and lysine residues in the beta 2 subunit of E. coli tryptophan synthase are conserved in the yeast enzyme [7].
• Inactivation of the beta 2 subunit and of the alpha 2 beta 2 complex of tryptophan synthase of Escherichia coli by the arginine-specific dicarbonyl reagent phenylglyoxal results from modification of one arginyl residue per beta monomer [8].

Biological context of TRP5

• A physical map of a contiguous DNA fragment of 60 kb, extending from the centromere to TRP5 on the left arm of the chromosome VII of Saccharomyces cerevisiae, strain IL125-2B, was established [9].
• Homologous sequence are observed in HIS1, HIS3, and in TRP5 upstream regions between copies of the repeat [10].
• The nucleotide sequence of the yeast gene TRP5 and its 5' and 3' flanking regions was determined [7].
• A 5' flanking region of TRP5 was shown by DNA/DNA hybridization to be present in multiple copies in the yeast genome [7].
• In contrast to the yeast TRP5 gene, which has no introns, the trp-3 coding region is interrupted by two introns 77 and 71 nucleotides in length [11].

Associations of TRP5 with chemical compounds

• TRP5 mRNA levels, measured by RNA/DNA hybridization, increased 2- to 7-fold in response to starvation for either tryptophan or histidine, indicating transcriptional regulation [7].
• Vector components consist of an S. occidentalis-derived autonomously replicating sequence (SwARS) and the Saccharomyces cerevisiae-derived TRP5 sequence for plasmid propagation and selection in the yeast hosts, an ori and an ampicillin-resistance sequence for propagation and selection in a bacterial host [12].
• The left arm of chromosome VII carries a tightly centromere linked marker, leu1 (leucine requirement), distal to leu1 in this order: trp5 (tryptophan requirement), cyh2 (recessive resistance to cycloheximide) and met 13 (requirement for methionine) [13].
• Isoniazid (INH) induced mitotic gene conversion at the trp5 locus of strain D7 of Saccharomyces cerevisiae [14].
• The dialysate from azide-treated barley seeds, applied at both pH 4.2 and pH 9, also significantly increased the frequency of locus-specific suppressor mutations to isoleucine independence and -- to a lesser extent -- reversions and/or gene conversions in the trp5 locus in growing cells of the diploid strain D7 [15].

Physical interactions of TRP5

• During mitosis, gene conversion events at the TRP5 locus on chromosome VII are coupled with conversion events at LEU1, a locus 18 cM away, 1200 times more frequently than would be expected for two independent acts of recombination [16].

Regulatory relationships of TRP5

• Sephadex G-100 gel filtration of a purified mixture of tryptophan-synthase-inactivating enzymes I and II from Saccharomyces cerevisiae, which had previously been identified as yeast proteinases A and B, yields two coincident peaks of tryptophan-synthase-inactivating activity and proteinase A and B activities [17].

Other interactions of TRP5

• Within a 31 kb region from PMA1 towards TRP5, a total of 12 transcription products ranging from 0.6 to 3.6 kb were identified in cells grown exponentially on rich medium [9].
• The plasmid-borne genes TRP2 to TRP5 were expressed and regulated normally in the frame of the general control [6].
• In yeast, coincident gene conversion events involving the LEU1 and TRP5 loci (16 cM apart) occur at frequencies that are far greater than is expected for two independent acts of recombination [18].
• The wild-type scl1+ gene was isolated by screening subclones of the 35-kb region between TRP5 and LEU1 for restoration of the ts phenotype in an SCL1-1 crl3-2 strain [19].
• The systems comprise auxotrophic host strains (trp5 in the case of S. occidentalis; trp5-10, his3 in the case of P. stipitis) and suitable transformation vectors [12].

References