ereB encodes erythromycin esterase type II, a plasmid-associated macrolide resistance enzyme in Escherichia coli. EreB inactivates erythromycin by hydrolyzing the macrolactone ring, yielding a modified antibiotic that no longer functions efficiently at the ribosome. GOA currently captures only a high-level antibiotic-response process, while the local UniProt record carries the broader carboxylic ester hydrolase activity.
Definition: Catalysis of the hydrolysis of the macrolactone ester bond of erythromycin or closely related macrolide antibiotics, resulting in antibiotic inactivation.
Justification: GO has only a broad carboxylic ester hydrolase term for Ere enzymes, while the AMR mechanism is specific hydrolysis of macrolide antibiotic lactone rings. The ARO mapping records this as a GO term request candidate.
Parent term: carboxylic ester hydrolase activity
Mappings:
Supporting Evidence:
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0046677 response to antibiotic | IEA GO_REF:0000002 | ACCEPT | Summary: Correct high-level biological-process annotation for an erythromycin-inactivation enzyme. Reason: EreB directly confers erythromycin resistance by enzymatic antibiotic inactivation. The key missing annotation is the molecular function. Supporting Evidence: file:genes/ECOLX/ereB/ereB-uniprot.txt This enzyme confers resistance to erythromycin through PMID:3523438 confers high-level resistance to erythromycin by inactivation in Escherichia coli. |
| GO:0052689 carboxylic ester hydrolase activity | RCA file:genes/ECOLX/ereB/ereB-uniprot.txt | NEW | Summary: NEW interim molecular-function annotation present in the UniProt flat file but absent from the fetched GOA TSV. Reason: Carboxylic ester hydrolase activity is a defensible broad parent for EreB, but it does not capture the macrolide/erythromycin lactone-ring substrate. A specific macrolide esterase term is proposed below. Supporting Evidence: file:genes/ECOLX/ereB/ereB-uniprot.txt DR GO; GO:0052689; F:carboxylic ester hydrolase activity PMID:3523438 The data obtained indicated that like ereA (Ounissi and Courvalin, 1985) ereB encodes an erythromycin esterase. |
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Download this section (compressed HTML)Q: Should the GO term be erythromycin-specific or generalized to macrolide lactone esterase activity?
Experiment: Measure EreB activity and product formation across 14-, 15-, and 16-membered macrolides to define whether an erythromycin-specific or macrolide-class term is the right GO scope.
Type: in vitro enzyme assay
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