A NEW CLASS OF LEISHMANIA-TROPICA MINICIRCLE MITOCHONDRIAL-DNA

A new class of mtDNA minicircle molecules with a circular length of 43 0 bp, i.e., approximately half of the ordinary mtDNA, was detected by electron microscopy in Leishmania tropica. Some characteristic structu ral elements of mtDNA, i.e., conservative and variable region includin g the presumable guiding RNA gene, were detected in the nucleotide seq uence of minicircle molecules, as well as CCAAT and TAGTTTGA sequences which may function as regulatory elements in RNA editing. Minicircles may serve as operative copies of standard molecules in RNA editing.