SPCC1259.09c

Summary: PAINT inference: protein X (E3-binding protein) is a structural component that tethers E3 to the E2 core.

Reason: The by-similarity UniProt function note (ECO:0000250; orthology to S. cerevisiae Pdx1 and mammalian PDHX, not an S. pombe assay) describes a non-catalytic tethering role, anchoring E3 to the E2 core; the protein carries the peripheral subunit-binding domain (PROSITE-ProRule PRU01170) that mediates such binding. This supports a structural/scaffolding role for the PAINT term.

Summary: ORFeome YFP screen: mitochondrion.

Summary: PAINT inference of mitochondrial location.

Reason: UniProt curates the location as mitochondrial matrix (ECO:0000305, curator inference) and predicts an N-terminal mitochondrial transit peptide (ECO:0000255); together with the ORFeome HDA row these support the root organelle term. No S. pombe sub-compartment assay exists.

Summary: UniProt/ARBA location mapping; consistent.

Reason: UniProt curates the location as mitochondrial matrix (ECO:0000305, curator inference) and predicts an N-terminal mitochondrial transit peptide (ECO:0000255); together with the ORFeome HDA row these support the root organelle term. No S. pombe sub-compartment assay exists.

Summary: Matrix location of this PDH complex subunit (inference or mapping); consistent.

Reason: Matrix location rests on UniProt's curator-inferred location (ECO:0000305) and the predicted mitochondrial transit peptide (ECO:0000255), consistent with membership of the matrix-resident PDH complex; it is not experimentally resolved in S. pombe.

Summary: Matrix location of this PDH complex subunit (inference or mapping); consistent.

Reason: Matrix location rests on UniProt's curator-inferred location (ECO:0000305) and the predicted mitochondrial transit peptide (ECO:0000255), consistent with membership of the matrix-resident PDH complex; it is not experimentally resolved in S. pombe.

Summary: Oxidative decarboxylation of pyruvate to acetyl-CoA by PDH.

Reason: UniProt's function note is by similarity (ECO:0000250) to characterised protein X orthologs (S. cerevisiae Pdx1, mammalian PDHX), not an S. pombe experiment; it states that E3 tethering is essential for a functional PDH complex, which supports participation in pyruvate decarboxylation to acetyl-CoA.

Summary: Oxidative decarboxylation of pyruvate to acetyl-CoA by PDH.

Reason: UniProt's function note is by similarity (ECO:0000250) to characterised protein X orthologs (S. cerevisiae Pdx1, mammalian PDHX), not an S. pombe experiment; it states that E3 tethering is essential for a functional PDH complex, which supports participation in pyruvate decarboxylation to acetyl-CoA.

Summary: InterPro mapping of acyltransferase activity from the peripheral-subunit-binding and E3-binding domains of this E2-like protein; protein X (E3-binding protein) is a noncatalytic structural subunit of the PDH complex, so the activity over-reaches.

Reason: Changed from KEEP_AS_NON_CORE, which would assert the activity is true. The mapping comes from InterPro PSBD (IPR004167) and E3-binding domain superfamily (IPR036625) entries, which are binding domains shared with the catalytic E2; the record lists no 2-oxoacid dehydrogenase acyltransferase catalytic domain (only Pfam Biotin_lipoyl). UniProt's by-similarity FUNCTION gives an anchoring (E3-tethering) role, and the PANTHER subfamily is protein X. In the characterised human ortholog, E3BP is described as the noncatalytic core component that tethers E3 (PMID:19240034). Evidence is by similarity and family membership; no S. pombe assay.

Summary: Component of the mitochondrial pyruvate dehydrogenase complex.

Reason: Complex membership rests on the by-similarity UniProt function note (ECO:0000250) that protein X anchors E3 to the E2 core of the PDH complex, and on PANTHER subfamily classification (PTHR23151:SF82, protein X component); no S. pombe complex purification is cached.

Summary: Component of the mitochondrial pyruvate dehydrogenase complex.

Reason: Complex membership rests on the by-similarity UniProt function note (ECO:0000250) that protein X anchors E3 to the E2 core of the PDH complex, and on PANTHER subfamily classification (PTHR23151:SF82, protein X component); no S. pombe complex purification is cached.