Fig 4.

Analysis of cytochrome c oxidase assembly in the absence of heme o or heme a synthase. (A) Proteins from mitochondria isolated from wild-type, cox10Δ, and cox15Δ cells were separated by BN-PAGE and analyzed by Western blotting using antiserum against different structural subunits and an assembly factor. The asterisk indicates monomeric COX. (B) Solubilized wild-type (WT) and cox10Δ mitochondria were subjected to immunoprecipitation using Coa3 or control antisera (total, 8%; eluate, 100%). (C) Comparison of complexes purified with Shy1^ProtA from solubilized mitochondria from the cox15Δ mutant, the cox15Δ mutant expressing Cox15^H368M from a plasmid (Cox15^H368M Shy1^ProtA), or the cox10Δ mutant on BN-PAGE.