c-Type Cytochrome Biogenesis Can Occur via a Natural Ccm System Lacking CcmH,CcmG, and the Heme-binding Histidine of CcmE |
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| Authors: | Alan D Goddard Julie M Stevens Feng Rao Despoina A I Mavridou Weelee Chan David J Richardson James W A Allen Stuart J Ferguson |
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| Institution: | From the ‡Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU and ;§Centre for Molecular and Structural Biochemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom |
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| Abstract: | The Ccm cytochrome c maturation System I catalyzes covalent attachment of heme to apocytochromes c in many bacterial species and some mitochondria. A covalent, but transient, bond between heme and a conserved histidine in CcmE along with an interaction between CcmH and the apocytochrome have been previously indicated as core aspects of the Ccm system. Here, we show that in the Ccm system from Desulfovibrio desulfuricans, no CcmH is required, and the holo-CcmE covalent bond occurs via a cysteine residue. These observations call for reconsideration of the accepted models of System I-mediated c-type cytochrome biogenesis. |
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| Keywords: | Chaperone Chaperonin Cytochrome c Cytochromes Heme Post-translational Modification Protein Assembly Cytochrome c Biogenesis Cytochrome c Maturation Heme Chaperone |
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