7f04

Cytochrome c-type biogenesis protein CcmABCD from E. coli in complex with Heme and ATP.

spinqualitylabelsall models 7f04, resolution 2.86Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7f04 is a 6 chain structure with sequence from Escherichia coli BL21(DE3). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 2.86Å Ligands: 3PE, ATP, HEM, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CCMA_ECOLI Part of the ABC transporter complex CcmAB involved in the biogenesis of c-type cytochromes; once thought to export heme, this seems not to be the case, but its exact role is uncertain. Responsible for energy coupling to the transport system. Publication Abstract from PubMed Cytochromes c use heme as a cofactor to carry electrons in respiration and photosynthesis. The cytochrome c maturation system I, consisting of eight membrane proteins (CcmABCDEFGH), results in the attachment of heme to cysteine residues of cytochrome c proteins. Since all c-type cytochromes are periplasmic, heme is first transported to a periplasmic heme chaperone, CcmE. A large membrane complex, CcmABCD has been proposed to carry out this transport and linkage to CcmE, yet the structural basis and mechanisms underlying the process are unknown. We describe high resolution cryo-EM structures of CcmABCD in an unbound form, in complex with inhibitor AMP-PNP, and in complex with ATP and heme. We locate the ATP-binding site in CcmA and the heme-binding site in CcmC. Based on our structures combined with functional studies, we propose a hypothetic model of heme trafficking, heme transfer to CcmE, and ATP-dependent release of holoCcmE from CcmABCD. CcmABCD represents an ABC transporter complex using the energy of ATP hydrolysis for the transfer of heme from one binding partner (CcmC) to another (CcmE). Structures of the CcmABCD heme release complex at multiple states.,Li J, Zheng W, Gu M, Han L, Luo Y, Yu K, Sun M, Zong Y, Ma X, Liu B, Lowder EP, Mendez DL, Kranz RG, Zhang K, Zhu J Nat Commun. 2022 Oct 28;13(1):6422. doi: 10.1038/s41467-022-34136-5. PMID:36307425 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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