Repression of the CaMV 35S promoter by the octopine synthase enhancer element.
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.
Gatz
C
C
Institut für Genbiologische Forschung Berlin GmbH, Germany.
Katzek
J
J
Prat
S
S
Heyer
A
A
D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics; D004742:Enhancer Elements, Genetic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D016385:TATA Box; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D000594:Amino Acid Oxidoreductases; C021903:D-octopine dehydrogenase