Structural highlights
Function
[MRRP3_HUMAN] Functions in mitochondrial tRNA maturation. Part of mitochondrial ribonuclease P, an enzyme composed of MRPP1/TRMT10C, MRPP2/HSD17B10 and MRPP3/KIAA0391, which cleaves tRNA molecules in their 5'-ends.[1]
Publication Abstract from PubMed
Mitochondrial RNA polymerase produces long polycistronic precursors that contain the mRNAs, rRNAs and tRNAs needed for mitochondrial translation. Mitochondrial RNase P (mt-RNase P) initiates the maturation of the precursors by cleaving at the 5' ends of the tRNAs. Human mt-RNase P is only active as a tripartite complex (mitochondrial RNase P proteins 1-3; MRPP1-3), whereas plant and trypanosomal RNase Ps (PRORPs)-albeit homologous to MRPP3-are active as single proteins. The reason for this discrepancy has so far remained obscure. Here, we present the crystal structure of human MRPP3, which features a remarkably distorted and hence non-productive active site that we propose will switch to a fully productive state only upon association with MRPP1, MRPP2 and pre-tRNA substrate. We suggest a mechanism in which MRPP1 and MRPP2 both deliver the pre-tRNA substrate and activate MRPP3 through an induced-fit process.
Structure of the nuclease subunit of human mitochondrial RNase P.,Reinhard L, Sridhara S, Hallberg BM Nucleic Acids Res. 2015 May 7. pii: gkv481. PMID:25953853[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Holzmann J, Frank P, Loffler E, Bennett KL, Gerner C, Rossmanith W. RNase P without RNA: identification and functional reconstitution of the human mitochondrial tRNA processing enzyme. Cell. 2008 Oct 31;135(3):462-74. PMID:18984158 doi:S0092-8674(08)01135-5
- ↑ Reinhard L, Sridhara S, Hallberg BM. Structure of the nuclease subunit of human mitochondrial RNase P. Nucleic Acids Res. 2015 May 7. pii: gkv481. PMID:25953853 doi:http://dx.doi.org/10.1093/nar/gkv481
