Sandbox WWC7

Introduction

Pentatricopeptide repeat (PPR) proteins are a family of sequence specific RNA-binding proteins which participate in organelle RNA metabolism. Although the mechanisms of RNA binding and the functions of PPR proteins are not fully understood, PPR proteins are thought to assist in RNA editing and translation, and they make up the majority of RNA-binding factors in plant organelles. PPR proteins are characterized by a series of tandem-repeat amino acid consensus sequences which form α-helix hairpins, and they can belong to one of two classes: P-class and PLS-class, with the P-class containing 35 amino acid repeats and the PLS-class containing 31-36 amino acid repeats. PPR10 is a P-class PPR protein found in the chloroplast of Zea mays.^[1]

Function

In the Zea Mays plastid, PPR10 binds specifically to the RNA oligonucleotides ATPH (17 nucleotides) and SPAJ (18 nucleotides) where it has been shown to shield the transcripts from ribonucleases. In addition to stabilizing these RNA sequences, PPR10 increases the rate at which they are translated.

References