FAA2 (YER015W; FAM1; UniProt P39518) notes
- Medium/long-chain acyl-CoA synthetase; C9-C13 preferred, C7-C17 tolerated PMID:8206942.
- Intraperoxisomal activation of medium-chain fatty acids PMID:8670886; peripheral, matrix side of peroxisomal membrane, PTS1 import [UniProt:P39518].
- Re-esterifies (V)LCFAs released by Pxa1p/Pxa2p PMID:22493507.
- Overexpression rescues nmt1-181 by activating endogenous C14:0 PMID:7962057.
- FAM1-1 suppressor gains a mitochondrial presequence; wild type lacks one PMID:7988550. Mitochondrial HDA hits likely peroxisome co-purification.
Pathway-context observations
- FAA2 is the only Faa paralog acting inside peroxisomes; it is the true activation step of peroxisomal beta-oxidation (medium-chain directly, long/very-long-chain as re-esterification after Pxa1/2). EC 6.2.1.3 assignment is OK but its signature activity is medium-chain (GO:0031956).
- ER IBA (from ER-type ACSLs) does not fit this PTS1 peroxisomal enzyme; cytosol RCA removed.
- GO:0015916 fatty-acyl-CoA transport IGI (PMID:18757502) left UNDECIDED (abstract only; acyl-CoA transport is Pxa1/Pxa2's).
Follow-up on the SGD description (2026-11-01)
- SGD notes that a mitochondrially targeted Faa2 form may arise from translation starting at a
non-canonical codon upstream of the annotated start. This is a comparative-genomics prediction only
PMID:31216041. No experiment has shown a mitochondrial Faa2 pool, so no location or isoform
was added.