REGULATION OF HISTIDINE BIOSYNTHESIS IN YEAST

我们的目标是了解酵母中基因活动的调控

Our goal is to understand the regulation of gene activity in the yeast Saccharomyces cerevisiae. The studies will focus on the nucleotide sequences which regulate transcription and translation of the histidine biosynthetic enzymes. Mutations in these sequences will be obtained by in vitro and in vovo mutagenesis. The mutations derived in vivo will be cloned by recombinant DNA procedures and then sequenced; those constructed in vitro will be inserted back into the genome for study by transformation. One of the sequences responsible for regulating genes in yeast is the transposable element, TY1. This element causes loss of function by insertion into the 5' non-coding region prior to the first ATG in the gene. We will study the insertion and excision of this element genetically and biochemically. Genetically, we will study the chromosome aberrations caused by the element as well as characterize mutations which enhance or diminish its insertion and excision. We will characterize the join points between the target gene and the element as well as the specificity of the recombination event by nucleotide sequence analysis. The regulatory effort of the insertion element on the transcription capabilities of the adajcent structural gene will be studied by Northern analysis.