6rwt
Crystal structure of the Cbp3 homolog from Brucella abortusCrystal structure of the Cbp3 homolog from Brucella abortus
Structural highlights
Publication Abstract from PubMedAssembly of the mitochondrial respiratory chain requires the coordinated synthesis of mitochondrial and nuclear encoded subunits, redox co-factor acquisition, and correct joining of the subunits to form functional complexes. The conserved Cbp3-Cbp6 chaperone complex binds newly synthesized cytochrome b and supports the ordered acquisition of the heme co-factors. Moreover, it functions as a translational activator by interacting with the mitoribosome. Cbp3 consists of two distinct domains: an N-terminal domain present in mitochondrial Cbp3 homologs and a highly conserved C-terminal domain comprising a ubiquinol-cytochrome c chaperone region. Here, we solved the crystal structure of this C-terminal domain from a bacterial homolog at 1.4 A resolution, revealing a unique all-helical fold. This structure allowed mapping of the interaction sites of yeast Cbp3 with Cbp6 and cytochrome b via site-specific photo-cross-linking. We propose that mitochondrial Cbp3 homologs carry an N-terminal extension that positions the conserved C-terminal domain at the ribosomal tunnel exit for an efficient interaction with its substrate, the newly synthesized cytochrome b protein. Structural basis for the interaction of the chaperone Cbp3 with newly synthesized cytochrome b during mitochondrial respiratory chain assembly.,Ndi M, Masuyer G, Dawitz H, Carlstrom A, Michel M, Elofsson A, Rapp M, Stenmark P, Ott M J Biol Chem. 2019 Nov 8;294(45):16663-16671. doi: 10.1074/jbc.RA119.010483. Epub , 2019 Sep 19. PMID:31537648[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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