... zinc knuckle domains(C-/-X-C-G-X3-H-X4-C, where / is an aromatic aminoacid and X is a variable amino acid) typical of retroviralnucleocapsid proteins and the presence of an glycine ⁄arginine ... affinities of La or CNBP for the 5¢ UTR, and the alternative binding of these pro-teins may lead, either alone or together with additionalfactors, to differential effects on the translation of rp-mRNAs ... Modulation of the concentrations and ⁄ or the biochemical activities of either CNBP or hnRNPK could influence the ability of the other factors tobind to the CT element and, thus, modulate CT ele-ment...