Human initiation factor eIF3 subunit b interacts with HCV IRES RNA through its N-terminal RNA recognition motif.
Many viral mRNAs contain a 5'-UTR RNA element called internal ribosome-entry site (IRES), which bypasses the requirement of some canonical initiation factors allowing cap-independent translation. The IRES of hepatitis-C virus drives translation by directly recruiting 40S ribosomal subunits and binds to eIF3 which plays a critical role in both cap-dependent and cap-independent translation. However, the molecular basis for eIF3 activity in either case remains enigmatic. Here we report that subunit b of the eIF3 complex directly binds to HCV IRES domain III via its N-terminal-RRM. Because eIF3b was previously shown to be involved in eIF3j binding, biological implications are discussed.
Pérard
Julien
J
Unit of Virus Host-Cell Interactions, UJF-EMBL-CNRS (UMR 5233), Grenoble, France.
Rasia
Rodolfo
R
Medenbach
Jan
J
Ayala
Isabel
I
Boisbouvier
Jérôme
J
Drouet
Emmanuel
E
Baudin
Florence
F
D020121:5' Untranslated Regions; D020816:Amino Acid Motifs; D039621:Eukaryotic Initiation Factor-3 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016174:Hepacivirus; D006801:Humans; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*
D020121:5' Untranslated Regions; D039621:Eukaryotic Initiation Factor-3; D021122:Protein Subunits; D012367:RNA, Viral