Structural insights into the dual activity of RNase J.
The maturation and stability of RNA transcripts is controlled by a combination of endo- and exoRNases. RNase J is unique, as it combines an RNase E-like endoribonucleolytic and a 5'-to-3' exoribonucleolytic activity in a single polypeptide. The structural basis for this dual activity is unknown. Here we report the crystal structures of Thermus thermophilus RNase J and its complex with uridine 5'-monophosphate. A binding pocket coordinating the phosphate and base moieties of the nucleotide in the vicinity of the catalytic center provide a rationale for the 5'-monophosphate-dependent 5'-to-3' exoribonucleolytic activity. We show that this dependence is strict; an initial 5'-PPP transcript cannot be degraded exonucleolytically from the 5'-end. Our results suggest that RNase J might switch promptly from endo- to exonucleolytic mode on the same RNA, a property that has important implications for RNA metabolism in numerous prokaryotic organisms and plant organelles containing RNase J orthologs.
Li de la Sierra-Gallay
Inés
I
FRC550, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
Zig
Léna
L
Jamalli
Ailar
A
Putzer
Harald
H
D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D012260:Ribonucleases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D016963:Thermus thermophilus / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D014542:Uridine Monophosphate / Q000737:chemistry
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D014542:Uridine Monophosphate; C526636:RNase J, Thermus thermophilus; D012260:Ribonucleases