Falcon (Edison Scientific) deep research report: Rat Amacr / AMACR (UniProt P70473) functional annotation
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AMACR is a cofactor-independent racemase/epimerase that inverts the C2 (alpha-carbon) stereochemistry of 2-methyl-branched acyl-CoA thioesters, interconverting (2R) and (2S) forms.
"AMACR is a **cofactor-independent racemase/epimerase** that catalyzes the **stereochemical inversion (racemization/epimerization) at C2 (α-carbon)** of **2-methyl-branched acyl-CoA thioesters**, converting **(2R) ↔ (2S)** forms."
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Pristanoyl-CoA and chain-shortened derivatives from branched-chain lipid metabolism are among the best-supported AMACR substrate classes.
"**Pristanoyl-CoA** and **chain-shortened derivatives** from branched-chain lipid metabolism."
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AMACR acts on CoA esters of bile-acid side-chain intermediates, particularly DHCA-CoA and THCA-CoA stereoisomers.
"**CoA esters of bile-acid side-chain intermediates**, particularly **DHCA-CoA** and **THCA-CoA** stereoisomers (commonly discussed as 25R/25S-related stereochemistry)."
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AMACR enables catabolism of dietary or isoprenoid-derived alpha-methyl-branched fatty acids in the phytanic to pristanic acid axis by converting the 2R-enantiomer to the 2S-enantiomer used by beta-oxidation.
"AMACR is positioned as a key node enabling catabolism of dietary or isoprenoid-derived **α-methyl-branched fatty acids**, particularly in the **phytanic → pristanic acid** metabolic axis, by converting the 2R-enantiomer to the 2S-enantiomer used by β-oxidation."
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AMACR participates in side-chain shortening of C27 bile-acid intermediates (DHCA/THCA) that contributes to formation of mature bile acids.
"AMACR also participates in metabolism/processing of **C27 bile-acid intermediates** (DHCA/THCA) during side-chain shortening steps that contribute to formation of mature bile acids."
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Rat-focused evidence places AMACR/racemase activity in both peroxisomes and mitochondria, with purification from rat liver mitochondrial fractions despite peroxisomal targeting features in the sequence.
"Primary rat-focused evidence indicates AMACR/racemase activity occurs in **both peroxisomes and mitochondria**, and that AMACR was purified from **rat liver mitochondrial fractions** (monomeric protein ~45–47 kDa) despite peroxisomal targeting features in the sequence."
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Rat AMACR ends in the tetrapeptide KANL, a PTS1-like peroxisomal targeting signal.
"Rat AMACR ends in the tetrapeptide **KANL**, described as a **PTS1-like** peroxisomal targeting signal."
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AMACR localization should be represented as dual-organelle biology with species- and study-dependent partitioning, not as exclusively peroxisomal.
"This should be represented as **dual-organelle biology with species- and study-dependent partitioning**, not as exclusively peroxisomal."