The two ATPase 6 mRNAs of Leishmania tarentolae differ at their 3' ends

We have determined the complete nucleotide sequence of ATPase 6 mRNA from Leishmania tarentolae. RNA editing occurs only in the 5' one-third of the mRNA and is the most extensive observed to date in this species. We have identified a potential gRNA sequence, encoded in a minicircle, for a portion of the edited sequence. The predicted amino acid sequence is about 85% homologous to that predicted from the more extensively edited Trypanosoma brucei ATPase 6 mRNA. The edited L. tarentolae mRNA exists as two distinct size classes which differ in the size of their 3' ends. Although variation in the length of the 3' untranslated region cannot be excluded, the size difference is probably to be due to variation in the length of the poly(A) tail.