1V76: Crystal Structure Of Archaeal Ribonuclease P Protein Ph1771p From Pyrococcus Horikoshii Ot3

Ribonuclease P (RNase P) is the endonuclease responsible for the removal of 5' leader sequences from tRNA precursors. The crystal structure of an archaeal RNase P protein, Ph1771p (residues 36-127) from hyperthermophilic archaeon Pyrococcus horikoshii OT3 was determined at 2.0 A resolution by X-ray crystallography. The structure is composed of four helices (alpha1-alpha4) and a six-stranded antiparallel beta-sheet (beta1-beta6) with a protruding beta-strand (beta7) at the C-terminal region. The strand beta7 forms an antiparallel beta-sheet by interacting with strand beta4 in a symmetry-related molecule, suggesting that strands beta4 and beta7 could be involved in protein-protein interactions with other RNase P proteins. Structural comparison showed that the beta-barrel structure of Ph1771p has a topological resemblance to those of Staphylococcus aureus translational regulator Hfq and Haloarcula marismortui ribosomal protein L21E, suggesting that these RNA binding proteins have a common ancestor and then diverged to specifically bind to their cognate RNAs. The structure analysis as well as structural comparison suggested two possible RNA binding sites in Ph1771p, one being a concave surface formed by terminal alpha-helices (alpha1-alpha4) and beta-strand beta6, where positively charged residues are clustered. A second possible RNA binding site is at a loop region connecting strands beta2 and beta3, where conserved hydrophilic residues are exposed to the solvent and interact specifically with sulfate ion. These two potential sites for RNA binding are located in close proximity. The crystal structure of Ph1771p provides insight into the structure and function relationships of archaeal and eukaryotic RNase P.
PDB ID: 1V76Download
MMDB ID: 29640
PDB Deposition Date: 2003/12/12
Updated in MMDB: 2004/11
Experimental Method:
x-ray diffraction
Resolution: 2  Å
Source Organism:
Similar Structures:
Biological Unit for 1V76: monomeric; determined by author
Molecular Components in 1V76
Label Count Molecule
Protein (1 molecule)
Rnase P Protein Ph1771p(Gene symbol: PH_RS08355)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

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