TY - JOUR
T1 - Transcription termination in the Escherichia coli dnaA gene is not mediated by the internal DnaA box
AU - Perez-Roger, I.
AU - Macian, F.
AU - Armengod, M. E.
PY - 1995
Y1 - 1995
N2 - DnaA protein is a DNA-binding protein which recognizes a 9-bp consensus sequence called the DnaA box. By binding to DnaA boxes, DnaA protein regulates initiation of chromosomal replication and transcription of several genes. The dnaA gene contains two DnaA boxes, one located in the regulatory region and one within the structural gene. In this paper, we explore the role of the internal DnaA box in dnaA expression because it has been proposed that the DnaA box-DnaA protein complex can block transcribing RNA polymerase. Firstly, we analyzed the degree of derepression of the dnaA gene, measured as β-galactosidase activity of a dnaA-lacZ fusion inserted onto the bacterial chromosome, produced by an extra copy number of the dnaA DnaA boxes carried by multicopy plasmids. Secondly, we analyzed repression produced by elevated levels of DnaA protein on single-copy dnaA-lacZ fusions containing or not containing the internal DnaA box. Our results indicate that the internal DnaA box does not play a regulatory role in dnaA expression.
AB - DnaA protein is a DNA-binding protein which recognizes a 9-bp consensus sequence called the DnaA box. By binding to DnaA boxes, DnaA protein regulates initiation of chromosomal replication and transcription of several genes. The dnaA gene contains two DnaA boxes, one located in the regulatory region and one within the structural gene. In this paper, we explore the role of the internal DnaA box in dnaA expression because it has been proposed that the DnaA box-DnaA protein complex can block transcribing RNA polymerase. Firstly, we analyzed the degree of derepression of the dnaA gene, measured as β-galactosidase activity of a dnaA-lacZ fusion inserted onto the bacterial chromosome, produced by an extra copy number of the dnaA DnaA boxes carried by multicopy plasmids. Secondly, we analyzed repression produced by elevated levels of DnaA protein on single-copy dnaA-lacZ fusions containing or not containing the internal DnaA box. Our results indicate that the internal DnaA box does not play a regulatory role in dnaA expression.
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U2 - 10.1128/jb.177.7.1896-1899.1995
DO - 10.1128/jb.177.7.1896-1899.1995
M3 - Article
C2 - 7896719
AN - SCOPUS:0028933556
SN - 0021-9193
VL - 177
SP - 1896
EP - 1899
JO - Journal of Bacteriology
JF - Journal of Bacteriology
IS - 7
ER -