Binding of the C6-zinc cluster protein, AFLR, to the promoters of aflatoxin pathway biosynthesis genes in Aspergillus parasiticus
Binding of the C6-zinc cluster protein, AFLR, to the promoters of aflatoxin pathway biosynthesis genes in Aspergillus parasiticus
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DOI：
10.1016/s0378-1119(99)00075-x
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发表时间：
1999-04-16
期刊：
影响因子：
3.5
通讯作者：
Cary, JW
中科院分区：
文献类型：
--
作者：
Ehrlich, KC;Montalbano, BG;Cary, JW
AFLR是一种锌(2)-半胱氨酸(6)-型序列特异性DNA结合蛋白，被认为是寄生黄曲霉和黄曲霉中黄曲霉毒素途径基因簇和黄曲霉杂色曲霉毒素基因簇中大多数基因表达所必需的。然而，目前尚不清楚AFLR是否与该簇中每个基因的启动子区域结合。最近发现多核拟青霉AFLR与5‘-TCGN(5)CGA-3’基序结合。在本研究中，我们检测了AFLR与寄生虫簇中11个基因的启动子区域的结合。根据凝胶迁移率改变分析，Nor1、pksA、Adha、Nora、ver1、omtA、orda和vbs基因在翻译起始点的200个碱基内至少有一个5‘-TCGN(5)CGA-3’结合位点，而pksA和ver1在上游还有一个额外的结合位点。虽然avnA的启动子区域没有这个基序，但AFLR在-110bp处与5‘-TCGCAGCCCGG-3’序列结合很弱。差异转录基因aflR/aflJ启动子中的一个区域与AFLR结合较弱，即使它含有最多只有7个碱基的5‘-TCGN(5)CGA-3’基序。这一部分位点可能被AFLR的单体形式识别。根据对16个可能的父本的比较，首选的结合序列是5‘-TCGSWNNSCGR-3’。(C)1999由爱思唯尔科学公司出版。版权所有。
AFLR is a Zn(2)Cys(6)-type sequence-specific DNA-binding protein that is thought to be necessary for expression of most of the genes in the aflatoxin pathway gene cluster in Aspergillus parasiticus and A. flavus, and the sterigmatocystin gene cluster in A. nidulans. However, it was not known whether AFLR bound to the promoter regions of each of the genes in the cluster. Recently, A. nidulans AFLR was shown to bind to the motif 5'-TCGN(5)CGA-3'. In the present study, we examined the binding of AFLR to promoter regions of 11 genes in the A. parasiticus cluster. Based on electrophoretic mobility shift assays, the genes nor1, pksA, adhA, norA, ver1, omtA, ordA, and, vbs, had at least one 5'-TCGN(5)CGA-3' binding site within 200 bp of the translation start site, and pksA and ver1 had an additional binding site further upstream. Although the promoter region of avnA lacked this motif, AFLR bound weakly to the sequence 5'-TCGCAGCCCGG-3' at -110 bp. One region in the promoter of the divergently transcribed genes aflR/aflJ bound weakly to AFLR even though it contained a site with at most only 7 bp of the 5'-TCGN(5)CGA-3' motif. This partial site may be recognized by a monomeric form of AFLR. Based on a comparison of 16 possible sires, the preferred binding sequence was 5'-TCGSWNNSCGR-3'. (C) 1999 Published by Elsevier Science B.V. All rights reserved.