UniProt functional annotation for P0A9G8



	UniProt functional annotation for P0A9G8

UniProt code: P0A9G8.

Organism: Escherichia coli (strain K12).

Taxonomy: Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.

Function: Functions as an intracellular molybdate sensor. The ModE-Mo complex acts as a repressor of the modABC operon, which is involved in the transport of molybdate (PubMed:8550508). Binds modA promoter DNA in the absence of molybdate, however molybdate binding confers increased DNA affinity (PubMed:9210473, PubMed:9044285). Binds the promoter of moaA activating its transcription; binding is not enhanced by molybdate (PubMed:9044285). The protein dimer binds the consensus palindrome sequence 5'-TATAT-N7-TAYAT-3' and a variant 5'-TGTGT-N7-TGYGT-3' (PubMed:9210473, PubMed:9044285, PubMed:16205910). Acts as a regulator of the expression of 67 genes, many of which encode molybdoenzymes, acts both directly and indirectly (PubMed:9466267, PubMed:10206709, PubMed:16205910). ModE also binds tungstate (PubMed:9210473, PubMed:11259434). {ECO:0000269|PubMed:10206709, ECO:0000269|PubMed:11259434, ECO:0000269|PubMed:16205910, ECO:0000269|PubMed:8550508, ECO:0000269|PubMed:9044285, ECO:0000269|PubMed:9210473, ECO:0000269|PubMed:9466267}.

Activity regulation: The ModE dimer binds two molecules of molybdate (MoO4(2-)) with a Kd of 0.8 uM, which results in major changes in the conformation of the DNA-binding domain and confers high-affinity DNA- binding to the transcription factor (PubMed:9210473, PubMed:9044285, PubMed:11259434, PubMed:12581638). Additionally molybdate binding moves the 2 Mop domains closer together, trapping the ligand between them (PubMed:12581638). Can also bind tungstate (PubMed:9210473, PubMed:11259434). Molybdate is bound at the dimer interface using residues from each monomer (PubMed:11259434, PubMed:12581638). {ECO:0000269|PubMed:11259434, ECO:0000269|PubMed:12581638, ECO:0000269|PubMed:9044285, ECO:0000269|PubMed:9210473}.

Subunit: Homodimer. {ECO:0000269|PubMed:9210473}.

Subcellular location: Cytoplasm {ECO:0000305|PubMed:9210473}.

Induction: Constitutively expressed at low levels; probably part of the modE-modF operon (PubMed:8564363, PubMed:8931336) (Probable). Does not seem to be autoregulated (PubMed:8931336). {ECO:0000269|PubMed:8564363, ECO:0000269|PubMed:8931336, ECO:0000305|PubMed:8550508}.

Domain: Deletion of the C-terminus (from residues 122 on) results in constitutive repression of modA (PubMed:8931336). Contains two major domains: the N-terminal domain I forms a winged helix-turn-helix motif and interacts with DNA (Probable). The C-terminal domain II is the olybdate-binding component and contains a tandem repeat of the Mop domain, each of which forms a beta-barrel (Probable) (PubMed:12581638). The N-terminal domain plays a major role in the dimerization of the protein whereas the C-terminal domain contributes to the stability of the complex (Probable). {ECO:0000269|PubMed:12581638, ECO:0000269|PubMed:8931336, ECO:0000305|PubMed:10075916, ECO:0000305|PubMed:12581638}.

Mass spectrometry: Mass=28271; Method=MALDI; Evidence={ECO:0000269|PubMed:8550508};

Disruption phenotype: Loss of repression of the modABC operon (PubMed:8564363, PubMed:8931336). Not essential for molybdopterin cofactor synthesis (PubMed:8931336). Increased dmsA expression under aerobic conditions and reduced expression under anaerobic conditions (PubMed:9466267). Decreased expression of hyc and narG (PubMed:10206709). {ECO:0000269|PubMed:10206709, ECO:0000269|PubMed:8564363, ECO:0000269|PubMed:8931336, ECO:0000269|PubMed:9466267}.

Similarity: Belongs to the ModE family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Escherichia coli (strain K12).
Taxonomy:		Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales; Enterobacteriaceae; Escherichia.



Function:		Functions as an intracellular molybdate sensor. The ModE-Mo complex acts as a repressor of the modABC operon, which is involved in the transport of molybdate (PubMed:8550508). Binds modA promoter DNA in the absence of molybdate, however molybdate binding confers increased DNA affinity (PubMed:9210473, PubMed:9044285). Binds the promoter of moaA activating its transcription; binding is not enhanced by molybdate (PubMed:9044285). The protein dimer binds the consensus palindrome sequence 5'-TATAT-N7-TAYAT-3' and a variant 5'-TGTGT-N7-TGYGT-3' (PubMed:9210473, PubMed:9044285, PubMed:16205910). Acts as a regulator of the expression of 67 genes, many of which encode molybdoenzymes, acts both directly and indirectly (PubMed:9466267, PubMed:10206709, PubMed:16205910). ModE also binds tungstate (PubMed:9210473, PubMed:11259434). {ECO:0000269\|PubMed:10206709, ECO:0000269\|PubMed:11259434, ECO:0000269\|PubMed:16205910, ECO:0000269\|PubMed:8550508, ECO:0000269\|PubMed:9044285, ECO:0000269\|PubMed:9210473, ECO:0000269\|PubMed:9466267}.


Activity regulation:		The ModE dimer binds two molecules of molybdate (MoO4(2-)) with a Kd of 0.8 uM, which results in major changes in the conformation of the DNA-binding domain and confers high-affinity DNA- binding to the transcription factor (PubMed:9210473, PubMed:9044285, PubMed:11259434, PubMed:12581638). Additionally molybdate binding moves the 2 Mop domains closer together, trapping the ligand between them (PubMed:12581638). Can also bind tungstate (PubMed:9210473, PubMed:11259434). Molybdate is bound at the dimer interface using residues from each monomer (PubMed:11259434, PubMed:12581638). {ECO:0000269\|PubMed:11259434, ECO:0000269\|PubMed:12581638, ECO:0000269\|PubMed:9044285, ECO:0000269\|PubMed:9210473}.
Subunit:		Homodimer. {ECO:0000269\|PubMed:9210473}.
Subcellular location:		Cytoplasm {ECO:0000305\|PubMed:9210473}.
Induction:		Constitutively expressed at low levels; probably part of the modE-modF operon (PubMed:8564363, PubMed:8931336) (Probable). Does not seem to be autoregulated (PubMed:8931336). {ECO:0000269\|PubMed:8564363, ECO:0000269\|PubMed:8931336, ECO:0000305\|PubMed:8550508}.
Domain:		Deletion of the C-terminus (from residues 122 on) results in constitutive repression of modA (PubMed:8931336). Contains two major domains: the N-terminal domain I forms a winged helix-turn-helix motif and interacts with DNA (Probable). The C-terminal domain II is the olybdate-binding component and contains a tandem repeat of the Mop domain, each of which forms a beta-barrel (Probable) (PubMed:12581638). The N-terminal domain plays a major role in the dimerization of the protein whereas the C-terminal domain contributes to the stability of the complex (Probable). {ECO:0000269\|PubMed:12581638, ECO:0000269\|PubMed:8931336, ECO:0000305\|PubMed:10075916, ECO:0000305\|PubMed:12581638}.
Mass spectrometry:		Mass=28271; Method=MALDI; Evidence={ECO:0000269\|PubMed:8550508};
Disruption phenotype:		Loss of repression of the modABC operon (PubMed:8564363, PubMed:8931336). Not essential for molybdopterin cofactor synthesis (PubMed:8931336). Increased dmsA expression under aerobic conditions and reduced expression under anaerobic conditions (PubMed:9466267). Decreased expression of hyc and narG (PubMed:10206709). {ECO:0000269\|PubMed:10206709, ECO:0000269\|PubMed:8564363, ECO:0000269\|PubMed:8931336, ECO:0000269\|PubMed:9466267}.
Similarity:		Belongs to the ModE family. {ECO:0000305}.