RegulonDB RegulonDB 10.7: Operon Form
   

norVW operon and associated TUs in Escherichia coli K-12 genome




Operon      
Name: norVW
This page displays every known transcription unit of this operon and their known regulation.


Transcription unit          
Name: norVW
Gene(s): norV, norW   Genome Browser M3D Gene expression COLOMBOS
Note(s): Although the NorR regulator protein can bind independently to each of the three binding sites in the norV promoter region controlling the flavorubredoxin gene expression, the presence of these three sites is required for in vivo induction of the norVW operon. Using protein cross-linking experiments it was demonstrated that NorR binds to the promoter of the flavorubredoxin gene as a trimer |CITS: [15694381]|.
Evidence: [IEP] Inferred from expression pattern
[ITC] Inferred through co-regulation
[LTED] Length of transcript experimentally determined
Reference(s): [1] Gardner AM., et al., 2003
[2] Hutchings MI., et al., 2002
[3] da Costa PN., et al., 2003
Promoter
Name: norVp
+1: 2832439
Sigma Factor: Sigma54 Sigmulon
Distance from start of the gene: 37
Sequence: ttatttatagagtaaaaacaatcagataaaaaactggcacgcaatctgcaattagcaagaCatctttttagaacacgctga
                                   -24         -12          +1                   
Note(s): This promoter was identified by microarray assays with a mutant σ54 strain and a σ54-overexpressing strain, and by σ54-related promoter element identification Zhao K,2010
We assigned a putative transcription start site to this promoter based on the observation that the majority of the σ54-dependent promoters, whose transcription start sites were determined experimentally, present a distance of 11 nucleotides between the transcription start site and the -12 box Barrios H,1999.
Evidence: [AIPP]
[HIPP]
[IEP]
[TIM] ; Method: Primer Extension
[TIM]
Reference(s): [4] Reitzer L., et al., 2001
[5] Tucker NP., et al., 2004
[6] Zhao K., et al., 2010
TF binding sites (TFBSs)
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote FNR repressor norVp 2832292 2832305 -140.5 aaactcatctTTGCCTCACTGTCAatttgactat nd [APIORCISFBSCS], [GEA] [3]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal IHF1 activator norVp 2832385 2832397 -48.0 aattttatttATAGAGTAAAAACaatcagataa nd [BPP] [5]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal IHF1 repressor norVp 2832449 2832461 17.0 catctttttaGAACACGCTGAATaaattgaggt nd [BPP] [5]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal NarL-Phosphorylated1 repressor norVp 2832353 2832368 -78.0 gatagtcattTTGACTACTCATTAATgggcataatt nd [APIORCISFBSCS], [GEA] [3]
proximal NarL-Phosphorylated repressor norVp 2832362 2832377 -69.0 tttgactactCATTAATGGGCATAATtttatttata nd [APIORCISFBSCS], [GEA] [3]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal NarP-Phosphorylated1 repressor norVp 2832353 2832368 -78.0 gatagtcattTTGACTACTCATTAATgggcataatt nd [APIORCISFBSCS], [GEA] [3]
proximal NarP-Phosphorylated repressor norVp 2832362 2832377 -69.0 tttgactactCATTAATGGGCATAATtttatttata nd [APIORCISFBSCS], [GEA] [3]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote NorR1 activator norVp 2832301 2832313 -132.0 tttgcctcacTGTCAATTTGACTatagatattg nd [AIBSCS], [BPP], [GEA] [1], [2], [5], [7], [8], [9], [10]
remote NorR2 activator norVp 2832322 2832334 -111.0 ctatagatatTGTCATATCGACCatttgattga nd [AIBSCS], [BPP], [GEA] [1], [2], [5], [7], [8], [9], [10]
proximal NorR3 activator norVp 2832346 2832358 -87.0 tttgattgatAGTCATTTTGACTactcattaat nd [AIBSCS], [BPP], [GEA] [1], [2], [5], [7], [8], [9], [10]
Note(s): 1IHF (-48 site) is fully occupied at IHF concentrations lower than those for IHF (17 site). The location of it is consistent with a role for IHF in bending DNA to bring NorR into contact with RNA polymerase.
1IHF (17 site) is considered a low-affinity IHF-binding site. Based on its position, it is inferred that it causes a negative
effect Tucker NP,20041NarP or NarL represses the transcription of the nor operon when Escherichia coli is grown with nitrite, which suggests that NarL and NarP proteins are competing with a transcriptional activator which is activated by nitrite and may binds to the nucleotide region in the vicinity of the putative NarL/NarP-binding site da Costa PN,2003
1NarP or NarL repress the transcription of the nor operon when Escherichia coli is grown with nitrite, suggesting that NarL and NarP proteins are competing with a transcriptional activator which is activated by nitrite, and may bind to the nucleotide region in the vacinity of the putative NarL/NarP-binding site da Costa PN,2003.
1This NorR-binding site ( -132), which contains the inverse repeat GTCA-(N3)-TGAC, is considered to be of low affinity.

2This NorR-binding site ( -111), which contains the inverted repeat GTCA-(N3)-CGAC, is considered to be of low -affinity.
3This NorR-binding site( -87), which is considered to be of high affinity, facilitates further binding of NorR to the adjacent site(s). In addition, it is primarily required for NorR-dependent norVW regulation, while one or both of the lower-affinity sites are involved in norR autoregulation. It contains the inverted repeat GTCA-(N3)-TGAC Tucker NP,2004Tucker N,2005.
2This NorR-binding site ( -132), which contains the inverse repeat GTCA-(N3)-TGAC, is considered to be of low affinity.

3This NorR-binding site ( -111), which contains the inverted repeat GTCA-(N3)-CGAC, is considered to be of low -affinity.
4This NorR-binding site( -87), which is considered to be of high affinity, facilitates further binding of NorR to the adjacent site(s). In addition, it is primarily required for NorR-dependent norVW regulation, while one or both of the lower-affinity sites are involved in norR autoregulation. It contains the inverted repeat GTCA-(N3)-TGAC Tucker NP,2004Tucker N,2005.

5NarP or NarL repress the transcription of the nor operon when Escherichia coli is grown with nitrite, suggesting that NarL and NarP proteins are competing with a transcriptional activator which is activated by nitrite, and may bind to the nucleotide region in the vacinity of the putative NarL/NarP-binding site da Costa PN,2003.
6NarP or NarL represses the transcription of the nor operon when Escherichia coli is grown with nitrite, which suggests that NarL and NarP proteins are competing with a transcriptional activator which is activated by nitrite and may binds to the nucleotide region in the vicinity of the putative NarL/NarP-binding site da Costa PN,2003
9IHF (-48 site) is fully occupied at IHF concentrations lower than those for IHF (17 site). The location of it is consistent with a role for IHF in bending DNA to bring NorR into contact with RNA polymerase.

10IHF (17 site) is considered a low-affinity IHF-binding site. Based on its position, it is inferred that it causes a negative
effect Tucker NP,2004




Reference(s)    

 [1] Gardner AM., Gessner CR., Gardner PR., 2003, Regulation of the nitric oxide reduction operon (norRVW) in Escherichia coli. Role of NorR and sigma54 in the nitric oxide stress response., J Biol Chem 278(12):10081-6

 [2] Hutchings MI., Mandhana N., Spiro S., 2002, The NorR protein of Escherichia coli activates expression of the flavorubredoxin gene norV in response to reactive nitrogen species., J Bacteriol 184(16):4640-3

 [3] da Costa PN., Teixeira M., Saraiva LM., 2003, Regulation of the flavorubredoxin nitric oxide reductase gene in Escherichia coli: nitrate repression, nitrite induction, and possible post-transcription control., FEMS Microbiol Lett 218(2):385-93

 [4] Reitzer L., Schneider BL., 2001, Metabolic context and possible physiological themes of sigma(54)-dependent genes in Escherichia coli., Microbiol Mol Biol Rev 65(3):422-44, table of contents

 [5] Tucker NP., D'Autr?aux B., Studholme DJ., Spiro S., Dixon R., 2004, DNA binding activity of the Escherichia coli nitric oxide sensor NorR suggests a conserved target sequence in diverse proteobacteria., J Bacteriol 186(19):6656-60

 [6] Zhao K., Liu M., Burgess RR., 2010, Promoter and regulon analysis of nitrogen assimilation factor, sigma54, reveal alternative strategy for E. coli MG1655 flagellar biosynthesis., Nucleic Acids Res 38(4):1273-83

 [7] Gardner AM., Helmick RA., Gardner PR., 2002, Flavorubredoxin, an inducible catalyst for nitric oxide reduction and detoxification in Escherichia coli., J Biol Chem 277(10):8172-7

 [8] Justino MC., Goncalves VM., Saraiva LM., 2005, Binding of NorR to three DNA sites is essential for promoter activation of the flavorubredoxin gene, the nitric oxide reductase of Escherichia coli., Biochem Biophys Res Commun 328(2):540-4

 [9] Tucker N., D'autreaux B., Spiro S., Dixon R., 2005, DNA binding properties of the Escherichia coli nitric oxide sensor NorR: towards an understanding of the regulation of flavorubredoxin expression., Biochem Soc Trans 33(Pt 1):181-3

 [10] Tucker NP., D'autreaux B., Spiro S., Dixon R., 2006, Mechanism of transcriptional regulation by the Escherichia coli nitric oxide sensor NorR., Biochem Soc Trans 34(Pt 1):191-4


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