MutS is the cytosolic ATP-dependent mismatch sensor that initiates post-replicative DNA mismatch repair. It recognizes base-pair mismatches and small insertion/deletion loops in duplex DNA, then uses its ATPase cycle to form a signaling clamp and recruit MutL for downstream strand incision and excision. In Pseudomonas putida KT2440, MutS and MutL constitute the two conserved recognition/incision components of a MutH-independent mismatch repair system.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0003684 damaged DNA binding | IEA GO_REF:0000104 | MARK AS OVER ANNOTATED | Summary: Compatible with mismatch recognition but too broad when mismatched DNA binding and ATP-dependent DNA damage sensor activity are available. Reason: The specific mismatch-sensor terms capture the core activity. |
| GO:0003690 double-stranded DNA binding | IEA GO_REF:0000118 | MARK AS OVER ANNOTATED | Summary: MutS acts on duplex DNA, but this generic binding term loses the mismatch specificity that defines its function. Reason: GO:0030983 is the informative substrate-specific term. |
| GO:0005524 ATP binding | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: Retain as non-core. ATP binding is required for the MutS conformational cycle, but the integrated sensor term is more informative. Reason: Correct mechanistic property subsumed by GO:0140664. |
| GO:0005829 cytosol | IEA GO_REF:0000118 | ACCEPT | Summary: Accept as the leaf-level location of the soluble bacterial mismatch sensor. Reason: Consistent with the reviewed protein record and chromosomal DNA substrate. |
| GO:0006298 mismatch repair | IEA GO_REF:0000120 | ACCEPT | Summary: Accept. KT2440 recombineering experiments directly tested permanent mutS deletion and established a MutS-dependent hierarchy of mismatch correction. Reason: Core biological process with direct organism-specific genetic support. Supporting Evidence: PMID:31599106 permanent deletion of mutS or transient loss of mutL activity |
| GO:0030983 mismatched DNA binding | IEA GO_REF:0000120 | ACCEPT | Summary: Accept as the substrate-specific recognition function of MutS. Reason: MutS is the mismatch-recognition component, unlike downstream MutL. Supporting Evidence: file:PSEPK/mutS/mutS-uniprot.txt mismatch recognition step |
| GO:0140664 ATP-dependent DNA damage sensor activity | IEA GO_REF:0000002 | ACCEPT | Summary: Accept as the most informative integrated molecular function. MutS couples recognition of mismatched DNA to an ATP-dependent signaling transition that initiates repair. Reason: Captures both lesion sensing and the essential ATPase-driven switch. |
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Download this section (compressed HTML)Q: Which mismatch classes most strongly stabilize the KT2440 MutS signaling clamp, and does the beta clamp recruit MutS at replication forks?
Experiment: Measure binding, ATPase activity, and sliding-clamp formation on matched duplexes and the mismatch classes ranked by the KT2440 recombineering study.
Hypothesis: KT2440 MutS ATPase switching differs quantitatively across mismatch classes.
Type: purified-protein mismatch recognition and ATPase assay
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Download this section (compressed HTML)MutS (Q88ME7; PP_1626) is the experimentally supported mismatch-recognition
component of KT2440 MMR. The direct study used permanent mutS deletion and
resolved a hierarchy of corrected mismatch classes
PMID:31599106.
The core functions retain both mismatched-DNA binding and ATP-dependent DNA
damage sensor activity: the first captures substrate recognition, while the
second captures the ATP-driven signaling transition. Generic damaged-DNA and
duplex-DNA binding terms were marked over-annotated.
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