全局转录因子Abf1p对酵母HIS7基因的调控

Regulation of the yeast HIS7 gene by the global transcription factor Abf1p.

作者信息

Springer C, Krappmann S, Künzler M, Zmasek C, Braus G H

机构信息

Institut für Mikrobiologie und Genetik Georg-August-Universität, Göttingen, Germany.

出版信息

Mol Gen Genet. 1997 Sep;256(2):136-46. doi: 10.1007/s004380050555.

DOI:10.1007/s004380050555

PMID:9349705

Abstract

The HIS7 gene of Saccharomyces cerevisiae encodes a bifunctional glutamine amidotransferase: cyclase that catalyzes the formation of biosynthetic precursors for histidine and adenine. HIS7 is activated by Gcn4p upon amino acid starvation and by the Bas1/2p complex in response to adenine limitation. Mutation analysis of the HIS7 promoter in a deltagcn4 background revealed a polyd(A/T) stretch and a d(CT) repeat as essential elements for Gcn4p-independent basal HIS7 transcription. The protein binding this element was enriched and identified as the multifunctional DNA-binding protein Abf1p. Abf1p binds specifically to the d(CT) repeat sequence, which represents a novel Abf1p-binding motif, and protects 17 nucleotides from digestion by DNase I. In addition, Abf1p binding causes bending of the HIS7 promoter structure.

摘要

酿酒酵母的HIS7基因编码一种双功能谷氨酰胺酰胺转移酶：环化酶，它催化组氨酸和腺嘌呤生物合成前体的形成。在氨基酸饥饿时，HIS7被Gcn4p激活；在腺嘌呤限制时，被Bas1/2p复合物激活。在deltagcn4背景下对HIS7启动子进行突变分析，发现一个多聚（A/T）序列和一个d（CT）重复序列是Gcn4p非依赖性基础HIS7转录的必需元件。结合该元件的蛋白质被富集并鉴定为多功能DNA结合蛋白Abf1p。Abf1p特异性结合d（CT）重复序列，该序列代表一种新的Abf1p结合基序，并保护17个核苷酸不被DNase I消化。此外，Abf1p的结合会导致HIS7启动子结构弯曲。