etr1

Summary: ORFeome screen cytoplasmic signal; Etr1 is a matrix enzyme.

Reason: Not the active location.

Summary: PAINT inference of mitochondrial location.

Reason: There is no sub-mitochondrial assay of S. pombe Etr1. The curated UniProt location (mitochondrion matrix) is by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the record also predicts an N-terminal mitochondrial transit peptide (residues 1-18, sequence analysis); the protein falls in the PANTHER mitochondrial enoyl-ACP reductase family. Two independent lines (ortholog location, transit peptide) therefore agree on a mitochondrial, matrix-facing soluble enzyme, which is also where the type II fatty acid synthase acts. The genome-wide ORFeome screen (PMID:16823372) reported a cytoplasmic signal instead, so the location is inferred rather than shown for this protein.

Summary: Matrix location (UniProt SubCell mapping of a by-similarity location).

Reason: There is no sub-mitochondrial assay of S. pombe Etr1. The curated UniProt location (mitochondrion matrix) is by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the record also predicts an N-terminal mitochondrial transit peptide (residues 1-18, sequence analysis); the protein falls in the PANTHER mitochondrial enoyl-ACP reductase family. Two independent lines (ortholog location, transit peptide) therefore agree on a mitochondrial, matrix-facing soluble enzyme, which is also where the type II fatty acid synthase acts. The genome-wide ORFeome screen (PMID:16823372) reported a cytoplasmic signal instead, so the location is inferred rather than shown for this protein.

Summary: Matrix location (similarity to S. cerevisiae Etr1).

Reason: There is no sub-mitochondrial assay of S. pombe Etr1. The curated UniProt location (mitochondrion matrix) is by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the record also predicts an N-terminal mitochondrial transit peptide (residues 1-18, sequence analysis); the protein falls in the PANTHER mitochondrial enoyl-ACP reductase family. Two independent lines (ortholog location, transit peptide) therefore agree on a mitochondrial, matrix-facing soluble enzyme, which is also where the type II fatty acid synthase acts. The genome-wide ORFeome screen (PMID:16823372) reported a cytoplasmic signal instead, so the location is inferred rather than shown for this protein.

Summary: Broad parent; Etr1 acts in mitochondrial type II fatty acid synthesis, captured by the fatty acid biosynthetic process row.

Reason: Correct but uninformative. By similarity to S. cerevisiae Etr1 (P38071) and PANTHER PTHR43981 membership, Etr1 is the enoyl-ACP reductase of mitochondrial fatty acid synthesis; GO:0006633 fatty acid biosynthetic process, asserted in this review, is_a this term. The PAINT node placement is not in question.

Summary: Transfer from S. cerevisiae Etr1: mtFAS.

Reason: Etr1 catalyses the enoyl reduction step of each elongation cycle of mitochondrial type II fatty acid synthesis, so it performs a step of the process. The curated UniProt function statement is by similarity to S. cerevisiae Etr1 (UniProtKB:P38071); no S. pombe experiment is cited.

Summary: Generic InterPro-derived parent of the specific activity, which is already annotated.

Reason: Oxidoreductase activity is correct but too general. By similarity to S. cerevisiae Etr1 (P38071; UniProt ECO:0000250) and family membership (InterPro IPR051034 Mito_Enoyl-ACP_Reductase, PANTHER PTHR43981), the specific activity is NADPH-dependent enoyl-ACP reduction, GO:0141148, already asserted in this review and an is_a descendant of this term.

Proposed replacements: enoyl-[acyl-carrier-protein] reductase (NADPH) activity

Summary: NADPH-dependent trans-2-enoyl-ACP reductase activity (EC/Rhea mapping).

Reason: The NADPH-dependent trans-2-enoyl-ACP reductase reaction (EC 1.3.1.104) and function are curated in UniProt by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the protein is classified in the PANTHER mitochondrial enoyl-[ACP] reductase family (PTHR43981, MDR/quinone oxidoreductase subfamily). No enzyme assay of the S. pombe protein is cited; the activity is an ortholog/family inference.

Summary: NADPH-dependent trans-2-enoyl-ACP reductase activity (transfer from S. cerevisiae Etr1).

Reason: The NADPH-dependent trans-2-enoyl-ACP reductase reaction (EC 1.3.1.104) and function are curated in UniProt by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the protein is classified in the PANTHER mitochondrial enoyl-[ACP] reductase family (PTHR43981, MDR/quinone oxidoreductase subfamily). No enzyme assay of the S. pombe protein is cited; the activity is an ortholog/family inference.

Summary: NADPH-dependent trans-2-enoyl-ACP reductase activity (similarity to S. cerevisiae Etr1).

Reason: The NADPH-dependent trans-2-enoyl-ACP reductase reaction (EC 1.3.1.104) and function are curated in UniProt by similarity to S. cerevisiae Etr1 (UniProtKB:P38071), and the protein is classified in the PANTHER mitochondrial enoyl-[ACP] reductase family (PTHR43981, MDR/quinone oxidoreductase subfamily). No enzyme assay of the S. pombe protein is cited; the activity is an ortholog/family inference.