A single amino acid change in a pathway-specific transcription factor results in differing degrees of constitutivity, hyperinducibility and derepression of several structural genes.
unYc462 is a gain-of-function mutation in the purine catabolism positive regulatory gene of Aspergillus nidulans. This allele leads to a constitutive, hyperinducible and derepressed expression of a least three genes controlled by uaY, and this occurs at different levels depending on the target gene. The uaYc462 allele was mapped physically in relation to known loss-of-function alleles and sequenced. uaYc462 is a one-base change in codon 222, resulting in a serine to leucine change. We propose that this mutation maps in a functional domain involved, directly or indirectly, in the interaction of UaY with other components of the transcriptional apparatus. A sequence similar to the motif surrounding serine 222 may play similar roles in the PPR1 and ADR1 proteins of Saccharomyces cerevisiae.
Oestreicher
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Institut de Génétique et de Microbiologie, Unité associée au CNRS 1354, Université de Paris-Sud, Centre d'Orsay, France.
Scazzocchio
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C
D000595:Amino Acid Sequence; D001233:Aspergillus nidulans; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009154:Mutation; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
C074682:ADR1 protein, S cerevisiae; D004268:DNA-Binding Proteins; C065682:PPR1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors