Download MendeleyStructural rearrangements in the C-terminal domain homolog of Orange Carotenoid Protein are crucial for carotenoid transfer.
Harris, D., Wilson, A., Muzzopappa, F., Sluchanko, N.N., Friedrich, T., Maksimov, E.G., Kirilovsky, D., Adir, N.(2018) Commun Biol 1: 125-125
- PubMed: 30272005
- DOI: https://doi.org/10.1038/s42003-018-0132-5
- Primary Citation of Related Structures:
6FEJ - PubMed Abstract:
A recently reported family of soluble cyanobacterial carotenoproteins, homologs of the C-terminal domain (CTDH) of the photoprotective Orange Carotenoid Protein, is suggested to mediate carotenoid transfer from the thylakoid membrane to the Helical Carotenoid Proteins, which are paralogs of the N-terminal domain of the OCP. Here we present the three-dimensional structure of a carotenoid-free CTDH variant from Anabaena ( Nostoc ) PCC 7120. This CTDH contains a cysteine residue at position 103. Two dimer-forming interfaces were identified, one stabilized by a disulfide bond between monomers and the second between each monomer's β-sheets, both compatible with small-angle X-ray scattering data and likely representing intermediates of carotenoid transfer processes. The crystal structure revealed a major positional change of the C-terminal tail. Further mutational analysis revealed the importance of the C-terminal tail in both carotenoid uptake and delivery. These results have allowed us to suggest a detailed model for carotenoid transfer via these soluble proteins.
Organizational Affiliation:
Schulich Faculty of Chemistry, Technion, 3200003, Haifa, Israel.
