RegulonDB RegulonDB 10.10: Operon Form
   

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




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


Transcription unit          
Name: bglGFB
Gene(s): bglB, bglF, bglG   Genome Browser M3D Gene expression COLOMBOS
Note(s): The bglGFB operon codes for one of four β-glucoside utilization systems in E. coli Moorthy S,2002. It codes for the autoregulatory antiterminator BglG, the EII glucoside transporter BglF, and the glucosidase BglB Schnetz K,1987. This operon is silent in wild-type cells grown in the lab due to the transcriptional regulator HNS Yasuzawa K,1992, but it can be activated by insertion of an IS element upstream of the operon, as well as by point mutations within the CRP-binding site or within gyrA or gyrB Schnetz K, Rak B,1992. Reynolds AE, Felton J, Wright A,1981. Reynolds AE,1986.
Once the operon is released from its silent state, it can be activated by Crp and repressed by Fis Gulati A,2000. Caramel A,2000. The bgl promoter is controlled by σS, whose effect is mediated by Crl Moorthy S,2002. Schnetz K.,2002. Once silencing ceases, bglGFB expression is controlled by the aromatic β-glucosides salicin and arbutin via an mRNA antitermination mechanism Schnetz K, Rak B,1988. BglG is activated by phosphorylation by HPr (or FPr) but is inactivated by additional phosphorylation by BglF at a different site Görke B, Rak B,1999. BglG is both phosphorylated and dephosphorylated by BglF, the enzyme II component of the Bgl sugar-transporting phosphotransferase system. The phosphorylation state of BglG at the BglF site is controlled by one of the β-glucoside inducers. In the absence of β-glucoside, BglG associates with and is phosphorylated by BglF in the cytoplasmic membrane. Addition of the inducer leads to dephosphorylation of BglG at the BglF site, and its localization to the cytoplasm where it forms homodimers and its transcriptional antitermination activity allows transcription of the bgl operon. The doubly phosphorylated form of BglG is unable to dimerize and bind to the target mRNA and does not have antiterminator activity Amster-Choder O, Wright A,1992. Schnetz K, Rak B,1990. Amster-Choder O, Wright A,1990. Amster-Choder O, Houman F, Wright A,1989. Lopian L, Nussbaum-Shochat A, O'Day-Kerstein K, Wright A, Amster-Choder O,2003. Ben-Zeev E, Fux L, Amster-Choder O, Eisenstein M,2005.
In the absence of the activated BglG homodimer, transcription from the bgl promoter is terminated at one of two rho-independent terminators. The first is located in the leader region of the bgl mRNA at a site immediately upstream of the bglG translation start site, and the second lies between bglG and bglF Schnetz K,1987. Mahadevan S, Wright A,1987. Schnetz K, Rak B,1988. BglG is able to bind to a site in the bgl mRNA which partially overlaps the rho-independent terminators, possibly blocking the formation of the terminator secondary structure and allowing transcription Houman F, Diaz-Torres MR, Wright A,1990. BlgG binding stabilizes the 5' end of the bgl mRNA Gulati A, Mahadevan S,2001. BglG also binds the β-subunit of RNA polymerase Nussbaum-Shochat A, Amster-Choder O,1999.
In addition to these well-established forms of transcriptional regulation, the bgl operon expression is also affected by StpA, Hfq, LeO, and BglJ, but their specific mechanisms remain to be determined Free A, Williams RM, Dorman CJ,1998. Tsui HC,1994. Ueguchi C,1998. Giel M,1996.
Repression of the bglGFB operon by StpA occurs only in the presence of the N-terminal H-NS protein domain, which comprises the core for dimerization Gueune H,2008.
The mRNA produced by the bglGFB operon has been observed mainly in the cellular membrane Kannaiah S, Livny J, Amster-Choder O,2019.
Evidence: [BTEI] Boundaries of transcription experimentally identified
[PM] Polar mutation
Reference(s): [1] Gulati A., et al., 2000
[2] Moorthy S., et al., 2002
[3] Schaefler S. 1967
[4] Schaefler S., et al., 1967
[5] Schnetz K., et al., 1987
[6] Yasuzawa K., et al., 1992
Promoter
Name: bglGp1
+1: 3906697
Distance from start of the gene: 130
Sequence: ggtcatatttttatcaatagcgcattgctattttctctgcacgcaattaaattaatttccGaacctggatgttcgttataa
Note(s): Induction of the pstB-phoU operon partially relieves repression of the bglp promoter by H-NS Rangarajan AA,2018
Evidence: [TIM]
Reference(s): [2] Moorthy S., et al., 2002
[7] Reynolds AE., et al., 1986
[8] Schnetz K. 2002
Terminator(s)
Type: rho-independent
Sequence: aaagaaagaaTTAACGCATCGCATCCAGACTGTTCTGAATGCGACGATAATTAAggtgctttaa
Reference(s): [5] Schnetz K., et al., 1987
Type: rho-independent
Sequence: tataaacaaaAAAACCCGACTTCACCAGTATTCTCTGGTTATGTCAGGTTTTgcctgcgaat
Reference(s): [5] Schnetz K., et al., 1987
TF binding sites (TFBSs)
[CRP,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal CRP-cyclic-AMP activator bglGp1 3906748 3906769 -61.5 caaagttaatAACTGCGAGCATGGTCATATTTttatcaatag nd [GEA], [AIBSCS], [BPP], [SM] [1], [14]
[Fis,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal Fis repressor bglGp1 3906717 3906731 -27.0 atagcgcattGCTATTTTCTCTGCAcgcaattaaa nd [BPP] [15]
proximal Fis repressor bglGp1 3906742 3906756 -52.0 tgcgagcatgGTCATATTTTTATCAatagcgcatt nd [BPP] [15]
[H-NS,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote H-NS repressor bglGp1 3906011 3906025 680.0 agttaatgcgCGAAATGCTGCAATTaataaaattt nd [GEA], [BPP] [10], [11], [16], [17]
[LeuO,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote LeuO activator bglGp1 3906805 3906825 -118.0 aataacttaaTTATTGGGATTTGTTATATATaactttataa nd [GEA], [IC], [BPP], [IC] [9], [10], [11]
remote LeuO activator bglGp1 3906836 3906856 -149.0 atagcgacaaATAATTCACCAGACAAATCCCaataacttaa nd [GEA], [IC], [BPP], [IC] [9], [10], [11]
[RcsB-BglJ,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote RcsB-BglJ activator bglGp1 3906783 3906802 -95.5 ttatatataaCTTTATAAATTCCTAAAATTacacaaagtt nd [GEA], [AIBSCS], [APIORCISFBSCS], [SM] [9], [11], [12], [13]
[StpA,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
nd StpA repressor bglGp1 nd nd nd nd nd [GEA], [BPP] [11], [18], [19]


Transcription unit          
Name: bglG
Gene(s): bglG   Genome Browser M3D Gene expression COLOMBOS
Evidence: [BTEI] Boundaries of transcription experimentally identified
Reference(s): [7] Reynolds AE., et al., 1986
[5] Schnetz K., et al., 1987
Promoter
Name: bglGp1
+1: 3906697
Distance from start of the gene: 130
Sequence: ggtcatatttttatcaatagcgcattgctattttctctgcacgcaattaaattaatttccGaacctggatgttcgttataa
Note(s): Induction of the pstB-phoU operon partially relieves repression of the bglp promoter by H-NS Rangarajan AA,2018
Evidence: [TIM]
Reference(s): [2] Moorthy S., et al., 2002
[7] Reynolds AE., et al., 1986
[8] Schnetz K. 2002
Terminator(s)
Type: rho-independent
Sequence: actccaaaaaAAAACCTGAAAAAAACGGCCTGACGTGAATCAAGCAATTTTTTTCAGGTTTTgcccgcttag
Reference(s): [5] Schnetz K., et al., 1987
TF binding sites (TFBSs)
[CRP,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal CRP-cyclic-AMP activator bglGp1 3906748 3906769 -61.5 caaagttaatAACTGCGAGCATGGTCATATTTttatcaatag nd [GEA], [AIBSCS], [BPP], [SM] [1], [14]
[Fis,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal Fis repressor bglGp1 3906717 3906731 -27.0 atagcgcattGCTATTTTCTCTGCAcgcaattaaa nd [BPP] [15]
proximal Fis repressor bglGp1 3906742 3906756 -52.0 tgcgagcatgGTCATATTTTTATCAatagcgcatt nd [BPP] [15]
[H-NS,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote H-NS repressor bglGp1 3906011 3906025 680.0 agttaatgcgCGAAATGCTGCAATTaataaaattt nd [GEA], [BPP] [10], [11], [16], [17]
[LeuO,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote LeuO activator bglGp1 3906805 3906825 -118.0 aataacttaaTTATTGGGATTTGTTATATATaactttataa nd [GEA], [IC], [BPP], [IC] [9], [10], [11]
remote LeuO activator bglGp1 3906836 3906856 -149.0 atagcgacaaATAATTCACCAGACAAATCCCaataacttaa nd [GEA], [IC], [BPP], [IC] [9], [10], [11]
[RcsB-BglJ,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
remote RcsB-BglJ activator bglGp1 3906783 3906802 -95.5 ttatatataaCTTTATAAATTCCTAAAATTacacaaagtt nd [GEA], [AIBSCS], [APIORCISFBSCS], [SM] [9], [11], [12], [13]
[StpA,-] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
nd StpA repressor bglGp1 nd nd nd nd nd [GEA], [BPP] [11], [18], [19]


Transcription unit          
Name: bglG
Gene(s): bglG   Genome Browser M3D Gene expression COLOMBOS
Evidence: [BTEI] Boundaries of transcription experimentally identified
Reference(s): [13] Salscheider SL., et al., 2014
[5] Schnetz K., et al., 1987
Promoter
Name: bglGp2
+1: 3906717
Distance from start of the gene: 150
Sequence: aagttaataactgcgagcatggtcatatttttatcaatagcgcattgctattttctctgcAcgcaattaaattaatttccg
Evidence: [TIM]
Reference(s): [13] Salscheider SL., et al., 2014
Terminator(s)
Type: rho-independent
Sequence: actccaaaaaAAAACCTGAAAAAAACGGCCTGACGTGAATCAAGCAATTTTTTTCAGGTTTTgcccgcttag
Reference(s): [5] Schnetz K., et al., 1987
TF binding sites (TFBSs)
[CRP,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal CRP-cyclic-AMP activator bglGp2 3906748 3906769 -41.5 caaagttaatAACTGCGAGCATGGTCATATTTttatcaatag nd [AIBSCS], [BPP], [GEA], [SM], [AIBSCS], [BPP], [SM] [1], [11], [14]
[RcsB-BglJ,+] Phrase
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
proximal RcsB-BglJ activator bglGp2 3906783 3906802 -75.5 ttatatataaCTTTATAAATTCCTAAAATTacacaaagtt nd [AIBSCS], [APIORCISFBSCS], [GEA], [SM], [AIBSCS], [APIORCISFBSCS], [SM] [9], [11], [12], [13]


RNA cis-regulatory element    
Regulation, transcriptional elongation  
Attenuator type: Transcriptional
Strand: reverse
  Structure type Energy LeftPos RightPos Sequence (RNA-strand)
  terminator -7.2 3905643 3905674 acctgaaaaaAATTGCTTGATTCACGTCAGGCCGTTTTTTTcaggtttttt
  terminator -16.9 3906586 3906631 cgcaggcaaaACCTGACATAACCAGAGAATACTGGTGAAGTCGGGTTTTTTTGTTtataaaaaag
  anti-terminator -11.0 3905667 3905718 tattattactGAGTAAAGGATTGTTACCGCACTAAGCGGGCAAAACCTGAAAAAAATTGCTtgattcacgt
  anti-terminator -10.1 3906617 3906659 taataaatgaCTGGATTGTTACTGCATTCGCAGGCAAAACCTGACATAACCAgagaatactg
  anti-anti-terminator -6.76 3905695 3905756 gccataaataTAGAGCGCGTGCGCAAAGAACACTGAAATATTATTACTGAGTAAAGGATTGTTACCGCACTaagcgggcaa
  anti-anti-terminator -6.0 3906641 3906691 ttccgaacctGGATGTTCGTTATAAAAACCATTAATAAATGACTGGATTGTTACTGCATTcgcaggcaaa
Notes: "The provided "Sequence" is that of the RNA strand, i.e. U's are shown instead of T's and regulators on the reverse strand will appear as the reverse complement of the sequence delimited by LeftPos-RigtPos"


Evidence    

 [TIM] Transcription initiation mapping

 [GEA] Gene expression analysis

 [AIBSCS] Automated inference based on similarity to consensus sequences

 [BPP] Binding of purified proteins

 [SM] Site mutation

 [IC] Inferred by curator

 [APIORCISFBSCS] A person inferred or reviewed a computer inference of sequence function based on similarity to a consensus sequence.


Reference(s)    

 [1] Gulati A., Mahadevan S., 2000, Mechanism of catabolite repression in the bgl operon of Escherichia coli: involvement of the anti-terminator BglG, CRP-cAMP and EIIAGlc in mediating glucose effect downstream of transcription initiation., Genes Cells 5(4):239-50

 [2] Moorthy S., Mahadevan S., 2002, Differential spectrum of mutations that activate the Escherichia coli bgl operon in an rpoS genetic background., J Bacteriol 184(14):4033-8

 [3] Schaefler S., 1967, Inducible system for the utilization of beta-glucosides in Escherichia coli. I. Active transport and utilization of beta-glucosides., J Bacteriol 93(1):254-63

 [4] Schaefler S., Maas WK., 1967, Inducible system for the utilization of beta-glucosides in Escherichia coli. II. Description of mutant types and genetic analysis., J Bacteriol 93(1):264-72

 [5] Schnetz K., Toloczyki C., Rak B., 1987, Beta-glucoside (bgl) operon of Escherichia coli K-12: nucleotide sequence, genetic organization, and possible evolutionary relationship to regulatory components of two Bacillus subtilis genes., J Bacteriol 169(6):2579-90

 [6] Yasuzawa K., Hayashi N., Goshima N., Kohno K., Imamoto F., Kano Y., 1992, Histone-like proteins are required for cell growth and constraint of supercoils in DNA., Gene 122(1):9-15

 [7] Reynolds AE., Mahadevan S., LeGrice SF., Wright A., 1986, Enhancement of bacterial gene expression by insertion elements or by mutation in a CAP-cAMP binding site., J Mol Biol 191(1):85-95

 [8] Schnetz K., 2002, Silencing of the Escherichia coli bgl operon by RpoS requires Crl., Microbiology 148(Pt 8):2573-8

 [9] Madhusudan S., Paukner A., Klingen Y., Schnetz K., 2005, Independent regulation of H-NS-mediated silencing of the bgl operon at two levels: upstream by BglJ and LeuO and downstream by DnaKJ., Microbiology 151(Pt 10):3349-59

 [10] Ueguchi C., Ohta T., Seto C., Suzuki T., Mizuno T., 1998, The leuO gene product has a latent ability to relieve bgl silencing in Escherichia coli., J Bacteriol 180(1):190-3

 [11] Venkatesh GR., Kembou Koungni FC., Paukner A., Stratmann T., Blissenbach B., Schnetz K., 2010, BglJ-RcsB heterodimers relieve repression of the Escherichia coli bgl operon by H-NS., J Bacteriol 192(24):6456-64

 [12] Giel M., Desnoyer M., Lopilato J., 1996, A mutation in a new gene, bglJ, activates the bgl operon in Escherichia coli K-12., Genetics 143(2):627-35

 [13] Salscheider SL., Jahn A., Schnetz K., 2014, Transcriptional regulation by BglJ-RcsB, a pleiotropic heteromeric activator in Escherichia coli., Nucleic Acids Res 42(5):2999-3008

 [14] Zheng D., Constantinidou C., Hobman JL., Minchin SD., 2004, Identification of the CRP regulon using in vitro and in vivo transcriptional profiling., Nucleic Acids Res 32(19):5874-93

 [15] Caramel A., Schnetz K., 2000, Antagonistic control of the Escherichia coli bgl promoter by FIS and CAP in vitro., Mol Microbiol 36(1):85-92

 [16] Dole S., Nagarajavel V., Schnetz K., 2004, The histone-like nucleoid structuring protein H-NS represses the Escherichia coli bgl operon downstream of the promoter., Mol Microbiol 52(2):589-600

 [17] Schnetz K., Wang JC., 1996, Silencing of the Escherichia coli bgl promoter: effects of template supercoiling and cell extracts on promoter activity in vitro., Nucleic Acids Res 24(12):2422-8

 [18] Gueune H., Durand MJ., Thouand G., DuBow MS., 2008, The ygaVP genes of Escherichia coli form a tributyltin-inducible operon., Appl Environ Microbiol 74(6):1954-8

 [19] Sun D., Mao X., Fei M., Chen Z., Zhu T., Qiu J., 2020, Histone-like Nucleoid-Structuring Protein (H-NS) Paralogue StpA Activates the Type I-E CRISPR-Cas System against Natural Transformation in Escherichia coli., Appl Environ Microbiol 86(14)

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