Identification of new selenocysteine tRNA[SER]SEC isoacceptors in human cell lines.

: The selenocysteine tRNA population was examined in a human T-cell line and in a human monocytic cell line for the occurrence of additional species of selenocysteine tRNA. At least three additional (and possibly more) selenocysteine isoacceptors were found which occur in minor levels as compared to the two major selenocysteine isoacceptors previously characterized. The possible significance of these newly observed species are discussed.