This study is aimed at identifying the molecular components involved in the post-transcriptional processing of the major low molecular weight viral RNA species (VA RNAI) synthesized in Adenovirus 2 infected KB cells. This involves the isolation and chromatographic purification of the nuclear nucleolytic enzyme(s) and the elucidation of the mechanism by which the extra nucleotide sequences of the precursor, V200 RNA, are excised. In addition to the processing enzyme(s), maturation of VA RNAI requires the presence of tRNA. I plan to identify the individual tRNA molecule(s) which modulate the in vitro maturation of VARNAI and determine their role in this process. This proposal is also directed toward identifying the "natural" substrate of the processing enzyme activity in the uninfected cell.