An RNA molecule copurifies with RNase P activity from<i>Xenopus laevis</i>oocytes

Utilizing a procedure for the purification of RNase P from Xenopus laevis germinal vesicle (GV) extracts, according to which the contamination by a large, cytoplasmic, cylindrical structure (1) is avoided, we demonstrate that the X.laevis enzyme, like the HeLa RNase P, is precipitated by anti-Th antibodies and an RNA molecule (XL RNA), 320 nucleotides long, copurifies with the activity. The sequence of XL RNA is 60% homologous to HeLa H1 RNA, therefore the two molecules seem related.