AnsB is the periplasmic L-asparaginase II of Escherichia coli. After export and signal-peptide cleavage, the enzyme assembles into a homotetramer that hydrolyzes L-asparagine to L-aspartate and ammonium. Its expression is responsive to cAMP and oxygen availability.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0004067 asparaginase activity | IBA GO_REF:0000033 | ACCEPT | Summary: AnsB is the active periplasmic asparaginase II. Reason: The native-equivalent recombinant enzyme was purified and assayed in PMID:1821783; curated reaction and structural work independently establish the same hydrolysis claim. Supporting Evidence: file:ECOLI/ansB/ansB-uniprot.txt Reaction=L-asparagine + H2O = L-aspartate + NH4(+); PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0004067 asparaginase activity | IDA PMID:1821783 Construction of expression systems for Escherichia coli aspa... | ACCEPT | Summary: AnsB is the active periplasmic asparaginase II. Reason: The native-equivalent recombinant enzyme was purified and assayed in PMID:1821783; curated reaction and structural work independently establish the same hydrolysis claim. Supporting Evidence: file:ECOLI/ansB/ansB-uniprot.txt Reaction=L-asparagine + H2O = L-aspartate + NH4(+); PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0004067 asparaginase activity | IEA GO_REF:0000120 | ACCEPT | Summary: AnsB is the active periplasmic asparaginase II. Reason: The native-equivalent recombinant enzyme was purified and assayed in PMID:1821783; curated reaction and structural work independently establish the same hydrolysis claim. Supporting Evidence: file:ECOLI/ansB/ansB-uniprot.txt Reaction=L-asparagine + H2O = L-aspartate + NH4(+); PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0006520 amino acid metabolic process | IEA GO_REF:0000002 | MODIFY | Summary: Specify L-asparagine breakdown. Reason: Asparaginase hydrolysis directly executes asparagine catabolism; the precise process is already retained. Proposed replacements: L-asparagine catabolic process Supporting Evidence: file:ECOLI/ansB/ansB-uniprot.txt Reaction=L-asparagine + H2O = L-aspartate + NH4(+); |
| GO:0006530 L-asparagine catabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: AnsB directly catalyzes asparagine catabolism. Reason: Hydrolysis generates aspartate and ammonium; therapeutic administration is not the basis for the native metabolic annotation. Supporting Evidence: file:ECOLI/ansB/ansB-uniprot.txt Reaction=L-asparagine + H2O = L-aspartate + NH4(+); |
| GO:0030288 outer membrane-bounded periplasmic space | IBA GO_REF:0000033 | ACCEPT | Summary: AnsB is exported into the bacterial periplasm. Reason: Osmotic-shock recovery of active protein in PMID:1821783 and the signal peptide in PMID:2407723 support outer-membrane-bounded periplasmic residence. This is not fungal cell-wall-bounded periplasm. Supporting Evidence: PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0030288 outer membrane-bounded periplasmic space | IDA PMID:15911532 Localization, annotation, and comparison of the Escherichia ... | ACCEPT | Summary: AnsB is exported into the bacterial periplasm. Reason: Osmotic-shock recovery of active protein in PMID:1821783 and the signal peptide in PMID:2407723 support outer-membrane-bounded periplasmic residence. This is not fungal cell-wall-bounded periplasm. Supporting Evidence: PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0030288 outer membrane-bounded periplasmic space | IDA PMID:24140104 Comparison of the large-scale periplasmic proteomes of the E... | ACCEPT | Summary: AnsB is exported into the bacterial periplasm. Reason: Osmotic-shock recovery of active protein in PMID:1821783 and the signal peptide in PMID:2407723 support outer-membrane-bounded periplasmic residence. This is not fungal cell-wall-bounded periplasm. Supporting Evidence: PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0030288 outer membrane-bounded periplasmic space | IDA PMID:4962587 Localization of the two-L-asparaginases in anaerobically gro... | ACCEPT | Summary: AnsB is exported into the bacterial periplasm. Reason: Osmotic-shock recovery of active protein in PMID:1821783 and the signal peptide in PMID:2407723 support outer-membrane-bounded periplasmic residence. This is not fungal cell-wall-bounded periplasm. Supporting Evidence: PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0032991 protein-containing complex | IDA PMID:8434007 Crystal structure of Escherichia coli L-asparaginase, an enz... | ACCEPT | Summary: AnsB assembles into an active homotetramer. Reason: Native structures and independent refolding into active tetramers (PMID:25309524) support homomeric assembly, identical-subunit binding and membership in a protein complex. The mutant study PMID:25040257 is corroborative, not the sole basis. Supporting Evidence: PMID:25309524 refolded into active tetrameric protein |
| GO:0042597 periplasmic space | IEA GO_REF:0000044 | MODIFY | Summary: AnsB is exported into the bacterial periplasm. Reason: Osmotic-shock recovery of active protein in PMID:1821783 and the signal peptide in PMID:2407723 support outer-membrane-bounded periplasmic residence. This is not fungal cell-wall-bounded periplasm. Proposed replacements: outer membrane-bounded periplasmic space Supporting Evidence: PMID:1821783 Most of the active recombinant enzyme can be released from the periplasmic space |
| GO:0042802 identical protein binding | IPI PMID:16858726 A complexomic study of Escherichia coli using two-dimensiona... | ACCEPT | Summary: AnsB assembles into an active homotetramer. Reason: Native structures and independent refolding into active tetramers (PMID:25309524) support homomeric assembly, identical-subunit binding and membership in a protein complex. The mutant study PMID:25040257 is corroborative, not the sole basis. Supporting Evidence: PMID:25309524 refolded into active tetrameric protein |
| GO:0042802 identical protein binding | IPI PMID:25040257 Crystal structure of active site mutant of antileukemic L-as... | ACCEPT | Summary: AnsB assembles into an active homotetramer. Reason: Native structures and independent refolding into active tetramers (PMID:25309524) support homomeric assembly, identical-subunit binding and membership in a protein complex. The mutant study PMID:25040257 is corroborative, not the sole basis. Supporting Evidence: PMID:25309524 refolded into active tetrameric protein |
| GO:0051289 protein homotetramerization | IDA PMID:25309524 Refolding and purification of recombinant L-asparaginase fro... | ACCEPT | Summary: AnsB assembles into an active homotetramer. Reason: Native structures and independent refolding into active tetramers (PMID:25309524) support homomeric assembly, identical-subunit binding and membership in a protein complex. The mutant study PMID:25040257 is corroborative, not the sole basis. Supporting Evidence: PMID:25309524 refolded into active tetrameric protein |
Loading supporting content…
Download this section (compressed HTML)Q: How does compartment-specific asparagine availability determine flux through AnsA versus AnsB in native growth conditions?
Loading supporting content…
Download this section (compressed HTML)Loading supporting content…
Download this section (compressed HTML)