Analysis of the downstream region of nodD3 P1 promoter by deletion and complementation tests in Sinorhizobium meliloti.
In Sinorhizobium meliloti, the nodD3 gene is transcriptionally controlled by two promoters, P1 and P2. Under P1, there is a 660 bp sequence including a small open reading frame, ORF2, followed by the nodD3 coding region. Genetic analysis using the different deletions on the 3' ends of P1 downstream sequence showed that the downstream sequence +1-+125nt is essential for P1 expression. Complementation, mutations and nodulation tests demonstrated that the ORF2 auto-represses P1 expression, while the P1 downstream sequence +1-+125nt counteracts it.
Chen
Di
D
Laboratory of Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes of Biological Science, Chinese Academy of Sciences, 200032, Shanghai, China.
Liu
Yanjie
Y
Zhu
Jiabi
J
Shen
Shanjiong
S
Yu
Guanqiao
G