title: Molecular basis for the recognition and cleavage of RNA by the bifunctional 5'-3' exo/endoribonuclease RNase J.
abstract: RNase J is a key member of the β-CASP family of metallo-β-lactamases involved in the maturation and turnover of RNAs in prokaryotes. The B. subtilis enzyme possesses both 5'-3' exoribonucleolytic and endonucleolytic activity, an unusual property for a ribonuclease. Here, we present the crystal structure of T. thermophilus RNase J bound to a 4 nucleotide RNA. The structure reveals an RNA-binding channel that illustrates how the enzyme functions in 5'-3' exoribonucleolytic mode and how it can function as an endonuclease. A second, negatively charged tunnel leads from the active site, and is ideally located to evacuate the cleaved nucleotide in 5'-3' exonucleolytic mode. We show that B. subtilis RNase J1, which shows processive behavior on long RNAs, behaves distributively for substrates less than 5 nucleotides in length. We propose a model involving the binding of the RNA to the surface of the β-CASP domain to explain the enzyme's processive action.
authors: FRC550, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
authors: Audrey
authors: A
authors: Dorléans
authors: Inés
authors: I
authors: Li de la Sierra-Gallay
authors: Jérémie
authors: J
authors: Piton
authors: Léna
authors: L
authors: Zig
authors: Laetitia
authors: L
authors: Gilet
authors: Harald
authors: H
authors: Putzer
authors: Ciarán
authors: C
authors: Condon
mesh_terms: D020816:Amino Acid Motifs; D001412:Bacillus subtilis / Q000201:enzymology; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D057075:Enzyme Assays; D007700:Kinetics; D008958:Models, Molecular; D011485:Protein Binding; D012313:RNA / Q000737:chemistry*; D012260:Ribonucleases / Q000737:chemistry*; D013379:Substrate Specificity; D013499:Surface Properties; D016963:Thermus thermophilus / Q000201:enzymology*
chemical_list: D012313:RNA; C526636:RNase J, Thermus thermophilus; D012260:Ribonucleases