1r6l
From Proteopedia
Crystal Structure Of The tRNA Processing Enzyme Rnase pH From Pseudomonas Aeruginosa
Structural highlights
FunctionRNPH_PSEAE Phosphorolytic exoribonuclease that removes nucleotide residues following the -CCA terminus of tRNA and adds nucleotides to the ends of RNA molecules by using nucleoside diphosphates as substrates (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 PubMedRNase PH is a phosphate-dependent exoribonuclease that catalyzes the removal of nucleotides at the 3' end of the tRNA precursor, leading to the release of nucleoside diphosphate, and generates the CCA end during the maturation process. The 1.9-A crystal structures of the apo and the phosphate-bound forms of RNase PH from Pseudomonas aeruginosa reveal a monomeric RNase PH with an alpha/beta-fold tightly associated into a hexameric ring structure in the form of a trimer of dimers. A five ion pair network, Glu-63-Arg-74-Asp-116-Arg-77-Asp-118 and an ion-pair Glu-26-Arg-69 that are positioned symmetrically in the trimerization interface play critical roles in the formation of a hexameric ring. Single or double mutations of Arg-69, Arg-74, or Arg-77 in these ion pairs leads to the dissociation of the RNase PH hexamer into dimers without perturbing the overall monomeric structure. The dissociated RNase PH dimer completely lost its binding affinity and catalytic activity against a precursor tRNA. Our structural and mutational analyses of RNase PH demonstrate that the hexameric ring formation is a critical feature for the function of members of the RNase PH family. Probing the functional importance of the hexameric ring structure of RNase PH.,Choi JM, Park EY, Kim JH, Chang SK, Cho Y J Biol Chem. 2004 Jan 2;279(1):755-64. Epub 2003 Oct 22. PMID:14573594[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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