Small membrane accessory subunit of the KdpFABC high-affinity potassium pump. KdpC participates in a transient nucleotide-dependent interaction with KdpB that can increase pump ATP-binding affinity, but KdpB remains the ATP-hydrolyzing subunit and KdpA provides potassium selectivity.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005524 ATP binding | IEA GO_REF:0000104 | KEEP AS NON CORE | Summary: Direct work on Escherichia coli KdpC reports ATP binding in the transient KdpB/KdpC/ATP catalytic-chaperone context. This supports the family-based annotation, although the broad binding term is not KdpC's defining role. Reason: Retain conservatively because the E. coli ortholog directly binds ATP and the conserved KdpC family assignment supports transfer to PSEPK. Keep it non-core because the interaction is complex-contextual and KdpC does not hydrolyze ATP. Supporting Evidence: PMID:21711450 binding to KdpC and ATP hydrolysis activity of KdpFABC were sensitive to the |
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Correct location for the integral KdpC accessory subunit. |
| GO:0006813 potassium ion transport | IEA GO_REF:0000120 | KEEP AS NON CORE | Summary: Correct but broader than potassium ion transmembrane transport. |
| GO:0008556 P-type potassium transmembrane transporter activity | IEA GO_REF:0000120 | ACCEPT | Summary: KdpC contributes as an accessory subunit to the collective KdpFABC pump activity but does not possess the complete transporter activity alone. Reason: The term is correct in substance. The qualifier should ideally be contributes_to rather than enables because KdpC is an accessory subunit; this relationship is captured in core_functions. |
| GO:0016020 membrane | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Correct but less precise than plasma membrane. |
| GO:0071805 potassium ion transmembrane transport | IEA GO_REF:0000118 | ACCEPT | Summary: Correct collective transport process of the complex containing KdpC. |
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Download this section (compressed HTML)Q: Is KdpC required for pump stability, regulation, or maximal transport in KT2440?
Experiment: Compare KdpFABC assembly and potassium uptake with and without kdpC.
Type: complex assembly and transport assay
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