Structural and Functional Perspectives on Mitochondrial LYR-Domain Proteins in Plants.

Arabidopsis thaliana contains 12 nuclear-encoded mitochondrial LYR (leucine/tyrosine/arginine) motif-containing proteins (LYRMs). Four of these proteins have been previously characterized in plants and were found to be involved in iron-sulfur cluster biogenesis and/or respiratory complex assembly. The function of the remaining eight is yet to be determined. Evolutionary analysis revealed that several LYRM proteins are unique to plants, while others share evolutionary ties with metazoans and fungi. Protein localization studies confirmed mitochondrial targeting for all 12 proteins, and expression profiles indicated high transcript abundance during germination and in developing tissues. Structural modeling highlighted the potential role of the LYR domain in protein-protein interactions with mitochondrial acyl carrier proteins, subunits of respiratory complexes, and chaperones. These findings enhance our understanding of the diverse roles of LYRM proteins in mitochondrial function in plants.