The N-terminal domain of the arenavirus L protein is an RNA endonuclease essential in mRNA transcription.
Arenaviridae synthesize viral mRNAs using short capped primers presumably acquired from cellular transcripts by a 'cap-snatching' mechanism. Here, we report the crystal structure and functional characterization of the N-terminal 196 residues (NL1) of the L protein from the prototypic arenavirus: lymphocytic choriomeningitis virus. The NL1 domain is able to bind and cleave RNA. The 2.13 Å resolution crystal structure of NL1 reveals a type II endonuclease α/β architecture similar to the N-terminal end of the influenza virus PA protein. Superimposition of both structures, mutagenesis and reverse genetics studies reveal a unique spatial arrangement of key active site residues related to the PD…(D/E)XK type II endonuclease signature sequence. We show that this endonuclease domain is conserved and active across the virus families Arenaviridae, Bunyaviridae and Orthomyxoviridae and propose that the arenavirus NL1 domain is the Arenaviridae cap-snatching endonuclease.
Morin
Benjamin
B
Architecture et Fonction des Macromolécules Biologiques, CNRS and Universités d'Aix-Marseille I et II, UMR 6098, ESIL Case 925, Marseille, France.
Coutard
Bruno
B
Lelke
Michaela
M
Ferron
François
F
Kerber
Romy
R
Jamal
Saïd
S
Frangeul
Antoine
A
Baronti
Cécile
C
Charrel
Rémi
R
de Lamballerie
Xavier
X
Vonrhein
Clemens
C
Lescar
Julien
J
Bricogne
Gérard
G
Günther
Stephan
S
Canard
Bruno
B
D002043:Bunyaviridae / Q000235:genetics / Q000378:metabolism; D020134:Catalytic Domain; D003460:Crystallization; D018360:Crystallography, X-Ray; D004720:Endonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008217:Lymphocytic choriomeningitis virus / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D016296:Mutagenesis; D009975:Orthomyxoviridae / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics*; D014158:Transcription, Genetic
D012333:RNA, Messenger; D012367:RNA, Viral; D004720:Endonucleases; D004722:Endoribonucleases