1y44
From Proteopedia
Crystal structure of RNase Z
Overview
Transfer RNAs (tRNAs) are synthesized as part of longer primary transcripts that require processing of both their 3' and 5' extremities in every living organism known. The 5' side is processed (matured) by the ubiquitously conserved endonucleolytic ribozyme, RNase P, whereas removal of the 3' tails can be either exonucleolytic or endonucleolytic. The endonucleolytic pathway is catalysed by an enzyme known as RNase Z, or 3' tRNase. RNase Z cleaves precursor tRNAs immediately after the discriminator base (the unpaired nucleotide 3' to the last base pair of the acceptor stem, used as an identity determinant by many aminoacyl-tRNA synthetases) in most cases, yielding a tRNA primed for addition of the CCA motif by nucleotidyl transferase. Here we report the crystal structure of Bacillus subtilis RNase Z at 2.1 A resolution, and propose a mechanism for tRNA recognition and cleavage. The structure explains the allosteric properties of the enzyme, and also sheds light on the mechanisms of inhibition by the CCA motif and long 5' extensions. Finally, it highlights the extraordinary adaptability of the metallo-hydrolase domain of the beta-lactamase family for the hydrolysis of covalent bonds.
About this Structure
1Y44 is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structural basis for substrate binding, cleavage and allostery in the tRNA maturase RNase Z., de la Sierra-Gallay IL, Pellegrini O, Condon C, Nature. 2005 Feb 10;433(7026):657-61. Epub 2005 Jan 16. PMID:15654328 Page seeded by OCA on Sat May 3 15:51:17 2008
