Saccharomyces cerevisiae alcohol dehydrogenase 1 (ADH1) promoter, medium truncation
A 707 bp 5' truncation of the S. cerevisiae ADH1 promoter, the constitutive promoter of the fermentative alcohol dehydrogenase gene. Drives constitutive expression in yeast at a more compact size than the full-length 1452 bp promoter (adh1-long), for constructs where the complete upstream region is not needed.
Origin: Saccharomyces cerevisiae, truncated ADH1 upstream region
Characteristics
Retains the ADH1 core promoter and transcription start sites but removes roughly 745 bp of upstream sequence present in the full-length 1452 bp promoter, including part of the region containing its UAS elements. ADH1 promoter constructs give constitutive expression that is markedly copy-number-dependent (about 30-fold higher activity on a 2-micron plasmid than on a CEN/ARS plasmid, versus about 3-fold for GPD), so absolute output from this truncation depends heavily on plasmid backbone.
Applications: Constitutive expression of heterologous genes, selection markers, and reporter constructs in S. cerevisiae where a smaller promoter fragment is preferred, e.g., to shorten a cloning insert or avoid restriction sites present in the full-length promoter.
Limitations: Loses part of the upstream activating sequence present in the full-length adh1-long promoter, and the resulting change in expression level for this specific truncation has not been directly measured in the cited literature. Constitutive activity cannot be induced or repressed on demand. Output is sensitive to plasmid copy number.