Gatz C, Katzek J, Prat S, Heyer A
Institut für Genbiologische Forschung Berlin GmbH, Germany.
FEBS Lett. 1991 Nov 18;293(1-2):175-8. doi: 10.1016/0014-5793(91)81180-g.
A 16 base-pair palindrome upstream of the Agrobacterium tumefaciens octopine synthase (ocs) gene functions as a positive regulatory element in plant cells (Ellis et al. (1987) EMBO J. 6, 3203-3208; Fromm et al. (1989) Plant Cell 1, 977-984). We have converted it into a negative element by locating two copies flanking the TATA-box of the constitutively expressed CaMV 35S promoter. The reduced promoter activity is very likely due to sterical hindrance of the ocs binding protein (OCSTF) x ocs complex with the transcription initiation complex. We propose that this type of constructs can be used for the identification of recognition sites for DNA-binding proteins which are labile in vitro as well as for determining the DNA-binding activity of a trans-acting factor in vivo.
根癌土壤杆菌章鱼碱合成酶（ocs）基因上游的一个16个碱基对的回文序列在植物细胞中作为正调控元件发挥作用（埃利斯等人（1987年），《欧洲分子生物学组织杂志》6，3203 - 3208；弗罗姆等人（1989年），《植物细胞》1，977 - 984）。我们通过在组成型表达的花椰菜花叶病毒35S启动子的TATA框两侧定位两个拷贝，将其转化为负调控元件。启动子活性降低很可能是由于ocs结合蛋白（OCSTF）x ocs复合物与转录起始复合物之间的空间位阻。我们提出，这种类型的构建体可用于鉴定在体外不稳定的DNA结合蛋白的识别位点，以及用于确定体内反式作用因子的DNA结合活性。
