2ohe
From Proteopedia
Structural and mutational analysis of tRNA-Intron splicing endonuclease from Thermoplasma acidophilum DSM 1728
Structural highlights
FunctionENDA_THEAC Endonuclease that removes tRNA introns. Cleaves pre-tRNA at the 5'- and 3'-splice sites to release the intron. The products are an intron and two tRNA half-molecules bearing 2',3' cyclic phosphate and 5'-OH termini. Recognizes a pseudosymmetric substrate in which 2 bulged loops of 3 bases are separated by a stem of 4 bp (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn archaea, RNA endonucleases that act specifically on RNA with bulge-helix-bulge motifs play the main role in the recognition and excision of introns, while the eukaryal enzymes use a measuring mechanism to determine the positions of the universally positioned splice sites relative to the conserved domain of pre-tRNA. Two crystallographic structures of tRNA intron-splicing endonuclease from Thermoplasma acidophilum DSM 1728 (EndA(Ta)) have been solved to 2.5-A and 2.7-A resolution by molecular replacement, using the 2.7-A resolution data as the initial model and the single-wavelength anomalous-dispersion phasing method using selenomethionine as anomalous signals, respectively. The models show that EndA(Ta) is a homodimer and that it has overall folding similar to that of other archaeal tRNA endonucleases. From structural and mutational analyses of H236A, Y229F, and K265I in vitro, we have demonstrated that they play critical roles in recognizing the splice site and in cleaving the pre-tRNA substrate. Structural and mutational analysis of tRNA intron-splicing endonuclease from Thermoplasma acidophilum DSM 1728: catalytic mechanism of tRNA intron-splicing endonucleases.,Kim YK, Mizutani K, Rhee KH, Nam KH, Lee WH, Lee EH, Kim EE, Park SY, Hwang KY J Bacteriol. 2007 Nov;189(22):8339-46. Epub 2007 Sep 7. PMID:17827289[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||
