The structure of Rph, an exoribonuclease from Bacillus anthracis, at 1.7 A resolution.
Rawlings, A.E., Blagova, E.V., Levdikov, V.M., Fogg, M.J., Wilson, K.S., Wilkinson, A.J.(2009) Acta Crystallogr Sect F Struct Biol Cryst Commun 65: 2-7
- PubMed: 19153445 
- DOI: https://doi.org/10.1107/S1744309108041511
- Primary Citation of Related Structures:  
3DD6 - PubMed Abstract: 
Maturation of tRNA precursors into functional tRNA molecules requires trimming of the primary transcript at both the 5' and 3' ends. Cleavage of nucleotides from the 3' stem of tRNA precursors, releasing nucleotide diphosphates, is accomplished in Bacillus by a phosphate-dependent exoribonuclease, Rph. The crystal structure of this enzyme from B. anthracis has been solved by molecular replacement to a resolution of 1.7 A and refined to an R factor of 19.3%. There is one molecule in the asymmetric unit; the crystal packing reveals the assembly of the protein into a hexamer arranged as a trimer of dimers. The structure shows two sulfate ions bound in the active-site pocket, probably mimicking the phosphate substrate and the phosphate of the 3'-terminal nucleotide of the tRNA precursor. Three other bound sulfate ions point to likely RNA-binding sites.
Organizational Affiliation: 
York Structural Biology Laboratory, Department of Chemistry, The University of York, England.