Functional Annotation of BenR (PP_3159; UniProt Q88I42) in Pseudomonas putida KT2440 - Falcon (Edison Scientific) Deep Research
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BenR family identity (AraC/XylS, XylS-related)
"BenR is a **DNA-binding transcriptional regulator** in the **AraC/XylS family**, closely related to the aromatic-response regulator XylS."
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BenR is a benzoate-responsive activator of the benABC dioxygenase cluster
"BenR is best understood as a **benzoate-responsive transcriptional activator** that turns on expression of genes needed to initiate benzoate catabolism, chiefly the **benABC** benzoate dioxygenase gene cluster."
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BenR acts as an intracellular cytosolic DNA-binding transcription factor at chromosomal promoters
"BenR functions as an **intracellular (cytosolic) DNA-binding transcription factor**, acting at chromosomal promoters (e.g., the benA/Pben promoter region) and capable of acting at related promoters in heterologous hosts when expressed there."
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benA-lacZ ~15-fold benzoate induction in wild type; catechol does not induce
"Cowles et al. constructed a **benA promoter–lacZ** transcriptional fusion and found that adding **benzoate** increased reporter activity by about **~15-fold** in wild-type *P. putida*, while **catechol did not induce** the fusion."
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benR mutant fails to induce benA, showing BenR is required for benzoate-dependent activation
"A **benR mutant** failed to induce the benA reporter in response to benzoate, demonstrating BenR is **required** for benzoate-dependent activation of benA/benABC."
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benA, benB, benC are cotranscribed in benzoate-grown cells (operon-level response)
"RT-PCR evidence indicates **benA, benB, benC** are cotranscribed in benzoate-grown cells, consistent with BenR controlling an operon-level response."
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BenR overexpression in E. coli activates benA-lacZ ~25-fold (direct activation)
"when BenR was **overexpressed in *E. coli*** carrying a benA-lacZ reporter, reporter expression rose by **~25-fold** compared with no benR."
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benR null mutant is defective for growth on benzoate; complemented by plasmid-borne benR
"A **benR null mutant** is defective for growth on benzoate, and plasmid-borne benR complements this phenotype."
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BenR mediates benzoate-mediated repression of pcaK 4-HBA uptake (substrate prioritization)
"Cowles et al. show BenR is involved in **benzoate-mediated repression** of **pcaK**, a 4-hydroxybenzoate (4-HBA) uptake system."
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ben promoter contains direct-repeat elements typical of XylS-family operator architecture
"note **direct-repeat elements** in the ben promoter region consistent with operator architectures described for XylS-family regulators."
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Summary annotation model - cytoplasmic benzoate-responsive AraC/XylS activator of benABC
"BenR (PP_3159; UniProt Q88I42) is best annotated as a **benzoate-responsive AraC/XylS-family transcriptional activator** that operates in the **cytoplasm** by binding and activating the **benA/Pben promoter** and turning on the **benABC** operon required for initiating benzoate catabolism (benzoate → catechol entry)."