The trypanosomatid Rieske iron-sulfur proteins have a cleaved presequence that may direct mitochondrial import.

We have cloned the gene that encodes subunit 4 of the T. brucei cytochrome-c reductase complex and a fragment of the C. fasciculata subunit 4 cDNA and have shown that subunit 4 is the Rieske iron-sulfur protein. The cleaved presequences of the trypanosomatid iron-sulfur proteins resemble conventional mitochondrial targeting presequences but are smaller than other eukaryotic iron-sulfur protein signal peptides.