The latter is the equivalent of the classical mitochondrial genome of other organisms and contains a number of genes coding for some of the components of the mitochondrial respiratory chain. Many of these genes are however incomplete and require editing of their transcribed RNA in order to give rise to a functional protein product. Editing is carried out with the help of a great number of guide RNAs, which are encoded by the many slightly different minicircles. Linear map of the 22-kb maxicircle of T. brucei . The genes above the line are transcribed from left to right, whereas the genes beneath the line are transcribed from the right to the left.
Shaded boxes indicate genes that are extensively or pan-edited .