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LacI Genetic Sensory Response Unit in Escherichia coli K-12 genome


Gensor Unit Map          
LacA LacI LacY LacZ 6-acetyl-b-D-galactoside b-D-galactoside ac-CoA allolactose b-D-galactose b-D-glucose CoA lacZYA lacZYA_mRNA a-D-lactose a-D-lactose_Ext a-D-melibiose a-D-melibiose_Ext LacI allolactose


Gensor Unit       
Name: LacI
Description: Molecular biology level
Detailed: In the absence of lactose LacI negatively regulates the expression of the genes required for transport and catabolism of D-lactose. Under these conditions, LacI binds its targed sites preventing the expression of its regulated genes. In the presence of D-lactose, it is converted to allolactose, LacI is modified to LacI-allolactose, unbinds its target sites, enabling the expression of its regulated genes.
Less detailed: In the absence of lactose LacI negatively regulates the expression of the genes needed for transport and catabolismof D-lactose.

Physiology level
Detailed: The presence of D-lactose induces the expression of genes involved with transport and catabolism of D-lactose. Under these conditions, the genes necessary for transformation of D-lactose to allolactose and D-galactoside to 6-acetyl-b-D-galactoside are expressed.
Less detailed: The presence of D-lactose induces the expression of genes needful for transport and catabolism of D-lactose.
Classification:
Groups: GUs related to carbon source utilization
Gene Ontology Terms (GO): biological_process GO:0008643 - carbohydrate transport
GO:0005990 - lactose catabolic process
GO:0015767 - lactose transport
GO:0055085 - transmembrane transport
cellular_component GO:0009341 - beta-galactosidase complex
GO:0016021 - integral component of membrane
GO:0005887 - integral component of plasma membrane
GO:0043231 - intracellular membrane-bounded organelle
GO:0016020 - membrane
GO:0005886 - plasma membrane
molecular_function GO:0031420 - alkali metal ion binding
GO:0004565 - beta-galactosidase activity
GO:0005351 - carbohydrate:proton symporter activity
GO:0008870 - galactoside O-acetyltransferase activity
GO:0004553 - hydrolase activity, hydrolyzing O-glycosyl compounds
GO:0030395 - lactose binding
GO:0015528 - lactose:proton symporter activity
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Components: Show/Hide Components Table (18 more...)
Function Name Type
simple_molecule 6-acetyl-beta-D-galactoside simple_molecule
protein LacA protein
protein LacI protein
complex LacI-allolactose complex
protein LacY protein
protein LacZ protein
simple_molecule acetyl-CoA simple_molecule
simple_molecule allolactose simple_molecule
simple_molecule beta-D-galactoside simple_molecule
simple_molecule coenzyme A simple_molecule
simple_molecule galactopyranose simple_molecule
simple_molecule glucopyranose simple_molecule
gene lacZYA gene
RNA lacZYA_mRNA RNA
simple_molecule lactose simple_molecule
simple_molecule lactose_Ext simple_molecule
simple_molecule melibiose simple_molecule
simple_molecule melibiose_Ext simple_molecule


Reactions       
Showing 10 reactions
LacI lacZYA lacZYA_mRNA
Name: lacZYA -> lacZYA_mRNA
Description: Transcription of transcription unit lacZYA. Reaction inhibition by LacI.
Type: transcription
Pathway Components: lacZYA - LacI -> lacZYA_mRNA
Components:
Function Name Type Evidence Reference(s)
inhibitor LacI protein nd nd
reactant lacZYA gene nd nd
product lacZYA_mRNA RNA nd nd
allolactose + LacI LacI-allolactose
Name: allolactose + LacI -> LacI-allolactose
Description: Reaction transforming allolactose, LacI into LacI-allolactose
Type: state transition
Pathway Components: allolactose + LacI -> LacI-allolactose
Components:
Function Name Type Evidence Reference(s)
reactant LacI protein nd nd
product LacI-allolactose complex nd nd
reactant allolactose simple_molecule nd nd
lacZYA_mRNA LacZ
Name: lacZYA_mRNA -> LacZ
Description: Translation of LacZ
Type: translation
Pathway Components: lacZYA_mRNA -> LacZ
Components:
Function Name Type Evidence Reference(s)
product LacZ protein nd nd
reactant lacZYA_mRNA RNA nd nd
LacZ lactose galactopyranose + glucopyranose
Name: lactose -> galactopyranose + glucopyranose
Description: Reaction transforming lactose into galactopyranose, glucopyranose
Type: state transition
Pathway Components: lactose - LacZ -> galactopyranose + glucopyranose
Components:
Function Name Type Evidence Reference(s)
catalyzer LacZ protein nd nd
product galactopyranose simple_molecule nd nd
product glucopyranose simple_molecule nd nd
reactant lactose simple_molecule nd nd
LacZ lactose allolactose
Name: lactose -> allolactose
Description: Reaction transforming lactose into allolactose
Type: state transition
Pathway Components: lactose - LacZ -> allolactose
Components:
Function Name Type Evidence Reference(s)
catalyzer LacZ protein nd nd
product allolactose simple_molecule nd nd
reactant lactose simple_molecule nd nd
lacZYA_mRNA LacY
Name: lacZYA_mRNA -> LacY
Description: Translation of LacY
Type: translation
Pathway Components: lacZYA_mRNA -> LacY
Components:
Function Name Type Evidence Reference(s)
product LacY protein nd nd
reactant lacZYA_mRNA RNA nd nd
LacY melibiose_Ext melibiose
Name: melibiose_Ext -> melibiose
Description: Transport of melibiose_Ext through a bacterial membrane, leading to the presence of melibiose inside the cell.
Type: transport
Pathway Components: melibiose_Ext - LacY -> melibiose
Components:
Function Name Type Evidence Reference(s)
catalyzer LacY protein nd nd
product melibiose simple_molecule nd nd
reactant melibiose_Ext simple_molecule nd nd
LacY lactose_Ext lactose
Name: lactose_Ext -> lactose
Description: Transport of lactose_Ext through a bacterial membrane, leading to the presence of lactose inside the cell.
Type: transport
Pathway Components: lactose_Ext - LacY -> lactose
Components:
Function Name Type Evidence Reference(s)
catalyzer LacY protein nd nd
product lactose simple_molecule nd nd
reactant lactose_Ext simple_molecule nd nd
lacZYA_mRNA LacA
Name: lacZYA_mRNA -> LacA
Description: Translation of LacA
Type: translation
Pathway Components: lacZYA_mRNA -> LacA
Components:
Function Name Type Evidence Reference(s)
product LacA protein nd nd
reactant lacZYA_mRNA RNA nd nd
LacA coenzyme A beta-D-galactoside + acetyl-CoA 6-acetyl-beta-D-galactoside + coenzyme A
Name: beta-D-galactoside + acetyl-CoA -> 6-acetyl-beta-D-galactoside + coenzyme A
Description: Reaction transforming beta-D-galactoside, acetyl-CoA into 6-acetyl-beta-D-galactoside, coenzyme A
Type: state transition
Pathway Components: beta-D-galactoside + acetyl-CoA - LacA - coenzyme A -> 6-acetyl-beta-D-galactoside + coenzyme A
Components:
Function Name Type Evidence Reference(s)
product 6-acetyl-beta-D-galactoside simple_molecule nd nd
catalyzer LacA protein nd nd
reactant acetyl-CoA simple_molecule nd nd
reactant beta-D-galactoside simple_molecule nd nd
inhibitor coenzyme A simple_molecule nd nd
product coenzyme A simple_molecule nd nd



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