Abstract
Many plant pentatricopeptide repeat (PPR) proteins are known to contain a highly conserved C-terminal DYW domain whose function is unknown. Recently, we have found that the recombinant DYW domains possessed endoribonuclease activity and cleaved before adenosine resides in the RNA molecule. To further prove this finding we prepared recombinant DYW proteins from 10 Physcomitrella patens PPR proteins and tested their endoribonuclease activity. Among ten PPR proteins, the recombinant DYW domains of PpPPR_56, PpPPR_71 and PpPPR_77 possessed endoribonuclease activity. This result suggests that some DYW-containing PPR proteins may catalyze site-specific cleavage of target RNA species.
