2 TYPES OF CHLOROPLAST GENE PROMOTERS IN CHLAMYDOMONAS-REINHARDTII
2 TYPES OF CHLOROPLAST GENE PROMOTERS IN CHLAMYDOMONAS-REINHARDTII
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DOI：
10.1073/pnas.89.8.3453
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发表时间：
1992-04-15
影响因子：
11.1
通讯作者：
BOGORAD, L
中科院分区：
文献类型：
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作者：
KLEIN, U;DECAMP, JD;BOGORAD, L
对莱茵衣藻质体atpB和16S rrna编码基因启动子的体内结构进行了分析。将含有衣藻叶绿体atpB或16S rrna编码基因启动子与大肠杆菌β -葡萄糖醛酸酶（GUS）报告基因偶联的嵌合构建物，通过微弹轰击将其稳定导入衣藻叶绿体。GUS基因阳性转化子叶绿体启动子的活性通过测定GUS转录物的丰度和测定GUS在体内的相对转录率来测定。对16S rRNA基因和atpB启动子片段的缺失分析表明，这两个启动子在结构上存在差异。16S rRNA基因启动子类似于细菌的sigma-70型，具有典型的-10和-35元件。另一方面，atpB启动子在-35区域缺乏保守基序，但在-10区域包含一个特征的八片段回文序列（TATAATAT），该序列在其他一些reinhardtii叶绿体基因的启动子序列中保守。为了获得最大的活性，atpB启动子需要转录起始位点上游几乎等于22个碱基对，下游几乎等于60个碱基对的序列。
Structures of the promoters of Chlamydomonas reinhardtii plastid atpB and 16S rRNA-encoding genes were analyzed in vivo. Chimeric constructs, containing the Chlamydomonas chloroplast atpB or 16S rRNA-encoding gene promoter coupled to the Escherichia coli uidA (beta-glucuronidase, GUS) reporter gene and bordered by C. reinhardtii chloroplast sequences, were stably introduced into the chloroplast of Chlamydomonas by microprojectile bombardment. Activity of the promoters in the chloroplast of GUS gene-positive transformants was assayed by measuring the abundance of GUS transcripts and determining the relative rates of GUS transcription in vivo. Deletion analyses of the 16S rRNA gene and atpB promoter fragments showed that the two promoters differ structurally. The 16S rRNA gene promoter resembles the bacterial sigma-70 type with typical -10 and -35 elements. The atpB promoter, on the other hand, lacks a conserved motif in the -35 region but contains, in the -10 region, a characteristic octameric palindrome (TATAATAT) that is conserved in the promoter sequences of some other C. reinhardtii chloroplast genes. For maximum activity, the atpB promoter requires sequences of almost-equal-to 22 base pairs upstream and almost-equal-to 60 base pairs downstream of the transcription start site.