Disease relevance of ilvY

• Overlapping transcription and termination of the convergent ilvA and ilvY genes of Escherichia coli [1].
• The nucleotide sequence of the ilvY and ilvC promoters and 5'-coding regions of Salmonella typhimurium LT2 have been determined [2].

High impact information on ilvY

• Evidence that this promoter coupling is DNA supercoiling-dependent is provided by the observation that a novobiocin-induced decrease in global negative superhelicity results in an increase in ilvY promoter activity and a decrease in ilvC promoter activity predicted by the in vitro data [3].
• Previous data have shown that transcription of the ilvC gene is induced by the acetohydroxy acid isomeroreductase substrates, acetohydroxybutyrate or acetolactate, and that this substrate induction of ilvC expression is mediated by a positive activator encoded by the ilvY gene [2].
• We report here the isolation and complete nucleotide sequence of the ilvY and ilvC genes [2].
• A model is presented in which the ilvY-encoded activator binds to an operator site in the overlapping promoter region and reciprocally regulates the transcription of the ilvY and ilvC genes [2].
• Based on the deduced amino acid sequences of the ilvA and ilvY genes, the translational termination codons for both genes are shown to be separated by 52 nucleotides [2].

Biological context of ilvY

• In this report, we use topoisomer sets of defined superhelical densities as DNA templates in a purified in vitro transcription system to demonstrate transcriptional coupling between the divergently transcribed ilvY and ilvC promoters of the ilvYC operon of Escherichia coli [4].
• Transcriptional activation at adjacent operators in the divergent-overlapping ilvY and ilvC promoters of Escherichia coli [5].
• One of these operators, designated O1 contains regions of dyad symmetry centered at position +17 relative to the ilvY transcriptional start site, and the second site, designated O2, contains an homologous inverted repeat sequence centered about the -35 region of the ilvC promoter [5].
• By use of plasmids carrying the positive-control factor structural gene ilvY, we were able to restore protein-synthesizing ability to these strains [6].

Associations of ilvY with chemical compounds

• Additionally, we discuss the role of acetohydroxybutyrate and acetolactate in ilvY transcriptional regulation [5].

Other interactions of ilvY

• The ilvY gene is transcribed in a direction opposite to the ilvC and ilvGMEDA genes [2].
• These experiments demonstrate that the converging transcripts from the ilvA and ilvY genes terminate in the coding region of the opposing gene [1].

References