Eukaryotic mRNA cap binding protein: purification by affinity chromatography on sepharose-coupled m7GDP.
A 24,000-dalton polypeptide that binds strongly and can be specifically crosslinked to the 5'-terminal cap structure m7GpppN in eukaryotic mRNAs has been detected in protein synthesis initiation factor preparations [Proc. Natl. Acad. Sci. USA (1978) 75, 4843--4847]. This polypeptide has been purified to apparent homogeneity by one chromatographic passage through an affinity resin prepared by coupling the levulinic acid O2',3'-acetal of m7GDP to AH-Sepharose 4B. Translation, in HeLa cell extracts, of capped mRNAs including Sindbis virus, reovirus, and rabbit globin mRNAs was stimulated by the cap-binding protein under conditions that did not increase translation of noncapped RNAs of encephalomyocarditis virus and satellite tobacco necrosis virus.
D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification*; D002474:Cell-Free System; D002846:Chromatography, Affinity / Q000379:methods; D008970:Molecular Weight; D014176:Protein Biosynthesis; D012314:RNA Cap Analogs / Q000378:metabolism; D012315:RNA Caps / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism
D002352:Carrier Proteins; D012314:RNA Cap Analogs; D012315:RNA Caps; D012333:RNA, Messenger