Structure of Mth11/Mth Rpp29, an essential protein subunit of archaeal and eukaryotic RNase P.
We have determined the solution structure of Mth11 (Mth Rpp29), an essential subunit of the RNase P enzyme from the archaebacterium Methanothermobacter thermoautotrophicus (Mth). RNase P is a ubiquitous ribonucleoprotein enzyme primarily responsible for cleaving the 5' leader sequence during maturation of tRNAs in all three domains of life. In eubacteria, this enzyme is made up of two subunits: a large RNA ( approximately 120 kDa) responsible for mediating catalysis, and a small protein cofactor ( approximately 15 kDa) that modulates substrate recognition and is required for efficient in vivo catalysis. In contrast, multiple proteins are associated with eukaryotic and archaeal RNase P, and these proteins exhibit no recognizable homology to the conserved bacterial protein subunit. In reconstitution experiments with recombinantly expressed and purified protein subunits, we found that Mth Rpp29, a homolog of the Rpp29 protein subunit from eukaryotic RNase P, is an essential protein component of the archaeal holoenzyme. Consistent with its role in mediating protein-RNA interactions, we report that Mth Rpp29 is a member of the oligonucleotide/oligosaccharide binding fold family. In addition to a structured beta-barrel core, it possesses unstructured N- and C-terminal extensions bearing several highly conserved amino acid residues. To identify possible RNA contacts in the protein-RNA complex, we examined the interaction of the 11-kDa protein with the full 100-kDa Mth RNA subunit by using NMR chemical shift perturbation. Our findings represent a critical step toward a structural model of the RNase P holoenzyme from archaebacteria and higher organisms.
Boomershine
William P
WP
Biochemistry Program, Ohio State University, Columbus, OH 43210, USA.
McElroy
Craig A
CA
Tsai
Hsin-Yue
HY
Wilson
Ross C
RC
Gopalan
Venkat
V
Foster
Mark P
MP
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D009682:Magnetic Resonance Spectroscopy; D017013:Methanobacteriaceae / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D043262:Ribonuclease P / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013816:Thermodynamics; D014158:Transcription, Genetic
D019843:Archaeal Proteins; D021122:Protein Subunits; D043262:Ribonuclease P