6gd7
Cytochrome c in complex with Sulfonato-calix[8]arene, H3 form with PEGCytochrome c in complex with Sulfonato-calix[8]arene, H3 form with PEG
Structural highlights
FunctionCYC1_YEAST Electron carrier protein. The oxidized form of the cytochrome c heme group can accept an electron from the heme group of the cytochrome c1 subunit of cytochrome reductase. Cytochrome c then transfers this electron to the cytochrome oxidase complex, the final protein carrier in the mitochondrial electron-transport chain. Publication Abstract from PubMedControlled protein assembly provides a means to regulate function. Supramolecular building blocks, including rigid macrocycles, have proven to be versatile triggers of protein assembly. Here, we show that sulfonato-calix[8]arene (sclx8) mediates the formation of cytochrome c tetramers in solution. This tetramer spontaneously disassembles at >/= 2 equivalents of sclx8 providing a remarkable example of "auto-regulation". Using X-ray crystallography we characterize in detail the sclx8 binding sites on cytochrome c. Crystal structures at different protein-ligand ratios reveal varying degrees (up to ~35 %) of protein surface coverage by the calixarene and suggest a mechanism for oligomer disassembly. The solution structure of the oligomer was characterized by small angle X-ray scattering. Overall, the data indicate calixarene-controlled protein assembly and disassembly without the requirement for a competitive inhibitor, and point to protein encapsulation by a flexible macrocycle. Auto-regulated Protein Assembly on a Supramolecular Scaffold.,Rennie M, Fox G, Perez J, Crowley PB Angew Chem Int Ed Engl. 2018 Aug 15. doi: 10.1002/anie.201807490. PMID:30109907[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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