Biochemical evidence supporting a mechanism for cap-independent and internal initiation of eukaryotic mRNA.

摘要: The role of eukaryotic initiation factor (eIF)4B in translation is somewhat uncertain, although it appears to stimulate a variety activities eIF-4A and eIF-4F. Using the model RNA-dependent ATP hydrolysis assay, ability eIF-4B eIF-4F was investigated. most dramatic effect increase affinity for RNA; no seen on ATP. This not case where stimulation occurs primarily through an Vmax change RNA. finding that can bind mRNA (lacking secondary structure), with essentially same degree effectiveness as would occur natural mRNAs presence eIF-4A, eIF-4B, eIF-4F, suggests possible both cap-independent internal initiation.