Inactivation of the nod box distal half-site allows tetrameric NodD to activate nodA transcription in an inducer-independent manner.
In Rhizobium leguminosarum, NodD can activate nodA transcription in response to inducer flavonoids. Here, we show that the inducible nodA promoter contains an intrinsic part through which NodD can activate nodA transcription in an inducer-independent manner. Evidence was provided that NodD binds to target DNA through anchoring the two half-sites of the nod box as a tetramer. An imperfect inverted repeat AT-N10-GAT was found in each half-site and is critical for NodD binding. Mutation of the inverted repeat of the nod box distal half-site allowed NodD to activate nodA transcription in an inducer-independent manner in vivo, and to modulate the DNA bending of the NodD-nod box complex in the absence of inducer in vitro.
Feng
Jie
J
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai, 200031, P.R. China.
Li
Qiang
Q
Hu
Hai-Liang
HL
Chen
Xiao-Chun
XC
Hong
Guo-Fan
GF
D000217:Acyltransferases / Q000235:genetics*; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D044950:Flavanones; D005419:Flavonoids / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D020868:Gene Silencing; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D016415:Sequence Alignment; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D001426:Bacterial Proteins; D044950:Flavanones; D005419:Flavonoids; C060773:NodD protein, Bacteria; D014157:Transcription Factors; D000217:Acyltransferases; C060770:NodA protein, Rhizobiales; C005273:naringenin