title: ATP/Mg++-dependent cross-linking of cap binding proteins to the 5' end of eukaryotic mRNA.
abstract: Two proteins of apparent molecular weights of 28,000 and 50,000 daltons were shown to recognize and cross-link specifically to the 5' cap end of oxidized reovirus mRNA. Cross-linking of these proteins to mRNA was ATP/Mg++ dependent, in sharp contrast to cross-linking of a 24K cap binding protein which was purified and characterized previously (Sonenberg, N., Rupprecht, K.M., Hecht, S.M. and Shatkin, A.J. (1979) Proc. Natl. Acad. Sci, USA 76, 4345-4349). Non-hydrolyzable analogues of ATP as well as other nucleotides did not substitute for ATP in the cross-linking reaction and Mg++ was significantly preferred over other divalent cations in cross-linking of the 28K and 50K dalton proteins. A model involving the function of the latter proteins in recognition and unwinding of the 5' end structure of capped eukaryotic mRNAs is suggested.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism*; D003432:Cross-Linking Reagents; D008274:Magnesium / Q000494:pharmacology*; D008970:Molecular Weight; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D012087:Reoviridae / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D003432:Cross-Linking Reagents; D039381:RNA Cap-Binding Proteins; D012315:RNA Caps; D012333:RNA, Messenger; D012367:RNA, Viral; D000255:Adenosine Triphosphate; D008274:Magnesium