Eukaryotic RNase P: role of RNA and protein subunits of a primordial catalytic ribonucleoprotein in RNA-based catalysis.
Ribonuclease P (RNase P) is an essential enzyme that processes the 5' leader sequence of precursor tRNA. Eubacterial RNase P is an RNA enzyme, while its eukaryotic counterpart acts as catalytic ribonucleoprotein, consisting of RNA and numerous protein subunits. To study the latter form, we reconstitute human RNase P activity, demonstrating that the subunits H1 RNA, Rpp21, and Rpp29 are sufficient for 5' cleavage of precursor tRNA. The reconstituted RNase P precisely delineates its cleavage sites in various substrates and hydrolyzes the phosphodiester bond. Rpp21 and Rpp29 facilitate catalysis by H1 RNA, which seems to require a phylogenetically conserved pseudoknot structure for function. Unexpectedly, Rpp29 forms a catalytic complex with M1 RNA of E. coli RNase P. The results uncover the core components of eukaryotic RNase P, reveal its evolutionary origin in translation, and provide a paradigm for studying RNA-based catalysis by other nuclear and nucleolar ribonucleoprotein enzymes.
Department of Molecular Biology, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
Hagit
H
Mann
Yitzhak
Y
Ben-Asouli
Aleks
A
Schein
Sana
S
Moussa
Nayef
N
Jarrous
D000818:Animals; D002384:Catalysis; D020134:Catalytic Domain / Q000235:genetics; D005057:Eukaryotic Cells / Q000201:enzymology*; D019143:Evolution, Molecular; D006801:Humans; D010802:Phylogeny; D011387:Prokaryotic Cells / Q000201:enzymology; D014176:Protein Biosynthesis / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D016337:RNA, Catalytic / Q000235:genetics / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D043262:Ribonuclease P / Q000235:genetics / Q000378:metabolism*
D021122:Protein Subunits; D016337:RNA, Catalytic; D012343:RNA, Transfer; D043262:Ribonuclease P