Summary: Cytoplasm is correct for this small soluble bacterial lipoyl carrier, but the cytosol row from the same source is retained.

Reason: Correct but general: the H protein is a soluble component of the bacterial glycine cleavage system with no signal peptide or transmembrane feature, so the TreeGrafter cytoplasm call is true. GO:0005829 cytosol, retained in this review from the same TreeGrafter source (bacterial PTHR11715 PAINT node PTN000196915, seeded by E. coli GcvH P0A6T9), is its descendant, so the row is modified to it under the module-wide rule for true parent terms whose retained child entails them.

Proposed replacements: cytosol

Summary: A soluble cytosolic location is plausible for the bacterial carrier but is not a core function.

Reason: TreeGrafter propagation from the bacterial PTHR11715 PAINT node PTN000196915, whose cytosol IBD is seeded by E. coli GcvH (P0A6T9). KT2440 GcvH proteins are bacterial members of that clade with no targeting or membrane feature, so the location holds; it is context rather than core function.

Summary: GcvH2 is the lipoyl-bearing carrier component of the four-protein system.

Reason: The reviewed UniProt record explicitly identifies P, H, T, and L proteins as system components.

Summary: GcvH2 is a lipoylation substrate; in the E. coli-type LipB/LipA route of KT2440 it does not relay the lipoyl group.

Reason: GcvH is an active lipoyl-relay intermediate only in lineages that build lipoyl domains through an H-protein relay (Firmicute LipM/LipL, yeast Lip2/Lip5 with Gcv3). KT2440 encodes the E. coli-type octanoyltransferase LipB (PP_4801) and lipoyl synthase LipA (PP_4800), which octanoylate and then sulfurate each apo-lipoyl domain directly, so GcvH1/GcvH2 are substrates of lipoylation, not participants. No PAINT IBD on PTHR11715 asserts protein lipoylation; the TreeGrafter row over-propagates a lineage-specific relay role to a protein that is only modified.

Summary: Intermediate shuttling by GcvH2 is required for this exact process.

Reason: UniProt describes transfer of the methylamine group from P protein to T protein on GcvH2.

Summary: This captures the lipoyl-arm carrier function of the H protein, which current GOA omits.

Reason: GO:0140104 is defined as 'Directly binding to a specific ion or molecule and delivering it either to an acceptor molecule or to a specific location'. The H protein carries the glycine-derived aminomethyl intermediate on its covalently attached lipoyl arm from the P protein to the T protein and presents the reduced arm to the L protein, which is carrier activity. Lipoic acid binding (GO:0031405) is not used for this role because GO binding is defined as non-covalent and the lipoyl group is covalently attached; GO:0140104 matches the glycine_cleavage_system module and the PomBase GO-CAM for the S. pombe H protein.