Leu-Tyr-Arg motif-containing protein

Leu-Tyr-Arg motif-containing proteins (LYRMs) form a superfamily of small (<15kDa), positively charged and predominantly mitochondrial proteins with an N-terminal leucine–tyrosine–arginine motif. However, the presence of this L–Y–R motif is not strictly required for LYRM classification, as membership is based on broader structural and functional criteria. LYRMs play key roles in essential mitochondrial processes, including oxidative phosphorylation (OXPHOS), mitochondrial translation, iron–sulfur (Fe–S) cluster assembly, or also in acetate metabolism. Their function is allosterically activated by acylated acyl carrier protein (acyl-ACP) provided by the mitochondrial fatty acid synthesis (mtFAS) pathway, in response to mitochondrial acetyl-CoA availability. This mode of activation enables them to function as late-stage electron transport chain (ETC) assembly factors.