The translation efficiency of ovalbumin mRNA is determined in part by a 5'-end hairpin structure.
We have investigated the role in translation of the secondary structure in the noncoding leader (NCL) sequence of ovalbumin mRNA. Deletion of a stem-loop structure from the mRNA 5'-end (hairpin-1) produced a 2.5-fold decrease in mRNA translation rate in both rabbit reticulocyte wheat germ cell-free systems. A corresponding 2-fold reduction in mRNA binding affinity for reticulocyte eucaryotic initiation factor 2 (eIF-2) was also observed. These effects were independent of mRNA capping. Both translation rate and eIF-2 binding affinity were restored by addition to the mRNA of a sequence containing a hairpin-1-like structure. The positive correlation between cell free translation rate and mRNA binding to eIF-2 suggests that hairpin-1 is both an initiation signal and part of a specific eIF-2 recognition site. Methylation interference indicated a direct interaction between eIF-2 and hairpin-1 of ovalbumin mRNA.
Department of Biochemistry, University of Tennessee, Memphis 38163.
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CD
Liarakos
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Theus
A S
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Watson
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Wahba
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Dholakia
D000818:Animals; D001483:Base Sequence; D002474:Cell-Free System; D002645:Chickens; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism; D008745:Methylation; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010047:Ovalbumin / Q000096:biosynthesis* / Q000235:genetics; D011485:Protein Binding; D014176:Protein Biosynthesis; D012315:RNA Caps / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry*; D012156:Reticulocytes / Q000378:metabolism; D012639:Seeds / Q000378:metabolism; D013329:Structure-Activity Relationship; D014908:Triticum / Q000378:metabolism
D015852:Eukaryotic Initiation Factor-2; D012315:RNA Caps; D012333:RNA, Messenger; D010047:Ovalbumin