betC

Summary: Intact COS accumulation supports uptake before BetC-dependent metabolism, but does not resolve the enzyme compartment.

Reason: The existing TreeGrafter cytoplasm inference is plausible and is not contradicted. KT2440 provides stronger target physiology than the other BetC comparators: the betC mutant still accumulates intact COS while failing to use it as carbon or nitrogen source (PMID:17116241). This favors uptake before BetC-dependent hydrolysis, but the accessible abstract does not identify a compartment-resolving assay or locate the enzyme. Accumulation alone does not discriminate cytoplasmic enzyme activity from another cell compartment. Choline-sulfatase family membership supports the chemistry, not the side of the membrane where it occurs. With full experimental localization evidence unavailable, retain this original row as UNDECIDED and omit a core location; the supported molecular function is unchanged.

Summary: Correct but general parent of the choline-sulfatase activity this gene already carries.

Reason: BetC hydrolyzes a sulfate ester, so the TreeGrafter term is true, but the choline-sulfatase family signatures, the KT2440 betC phenotype and the direct biochemistry of the Sinorhizobium ortholog support the specific child term choline-sulfatase activity (GO:0047753), already accepted on this gene. Treated the same way as the S. meliloti ortholog O69787.

Proposed replacements: choline-sulfatase activity

Summary: Accept exact choline-sulfatase activity as the core molecular function.

Reason: KT2440 betC loss prevents use of accumulated choline-O-sulfate as carbon or nitrogen source, and Q88RQ2 carries specific choline-sulfatase family signatures. Recombinant 1021/O69787 biochemistry supplies comparative evidence for this reaction. Together these support the target activity without claiming isolated Q88RQ2 kinetics, transferring phosphorylcholine activity, or identifying the COS importer.