RNA-binding specificity landscape of the pentatricopeptide repeat protein PPR10.

Pentatricopeptide repeat (PPR) proteins comprise a large family of helical repeat proteins that influence gene expression in mitochondria and chloroplasts. PPR tracts can bind RNA via a modular one repeat-one nucleotide mechanism in which the nucleotide is specified by the identities of several amino acids in each repeat. This mode of recognition, the so-called PPR code, offers opportunities for the prediction of native PPR binding sites and the design of proteins to bind specified RNAs However, a deep understanding of the parameters that dictate the affinity and specificity of PPR-RNA interactions is necessary to realize these goals.