MRP1 and MRP2 are mitochondrial RNA binding proteins that form a heteromeric complex. The MRP1/MRP2 heterotetrameric complex binds to guide RNAs and stabilises them in an unfolded conformation suitable for RNA-RNA hybridisation. Each MRP subunit adopts a 'whirly' transcription factor fold [1].

1: Crystal structures of T. brucei MRP1/MRP2 guide-RNA binding complex reveal RNA matchmaking mechanism. Schumacher MA, Karamooz E, Zikova A, Trantirek L, Lukes J; Cell. 2006;126:701-711. PMID:16923390