Identification of mitochondrial Complex II subunits SDH3 and SDH4 and ATP synthase subunits a and b in Plasmodium spp.

While most protist mitochondrial enzymes could be identified in database, the membrane anchor subunits of Complex II and F0F1-ATP synthase of malaria parasites are not annotated. Based on the presence of structural fingerprints or proteomics data from other protists, here we present their candidates. In contrast to canonical subunits, Plasmodium Complex II anchors have two transmembrane helices and may coordinate heme b via Tyr in place of His. Transmembrane helix IV of ATP synthase subunit a lacks an essential Arg residue. Membrane anchors of Plasmodium Complex II and ATP synthase are divergent from orthologs and promising targets for new chemotherapeutics. (C) 2009 Elsevier B.V. and Mitochondria Research Society. All rights reserved.