6S5L

Anabaena Apo-C-Terminal Domain Homolog Of The Orange Carotenoid Protein In Native Conditions

Summary for 6S5L

• Entry DOI: 10.2210/pdb6s5l/pdb
• Descriptor: All4940 protein (2 entities in total)
• Functional Keywords: ocp, orange carotenod protein, carotenoid transfer, ctdh, apoctdh, ctt, photosynthesis
• Biological source: Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576)
• Total number of polymer chains: 12
• Total formula weight: 181609.37

Authors

Harris, D.,Muzzopappa, F.,Kirilovsky, D.,Adir, N. (deposition date: 2019-07-01, release date: 2020-05-13, Last modification date: 2024-10-23)

Primary citation

Harris, D.,Muzzopappa, F.,Glaser, F.,Wilson, A.,Kirilovsky, D.,Adir, N.
Structural dynamics in the C terminal domain homolog of orange carotenoid Protein reveals residues critical for carotenoid uptake.
Biochim Biophys Acta Bioenerg, 1861:148214-148214, 2020

PubMed Abstract: The structural features enabling carotenoid translocation between molecular entities in nature is poorly understood. Here, we present the three-dimensional X-ray structure of an expanded oligomeric state of the C-terminal domain homolog (CTDH) of the orange carotenoid protein, a key water-soluble protein in cyanobacterial photosynthetic photo-protection, at 2.9 Å resolution. This protein binds a canthaxanthin carotenoid ligand and undergoes structural reorganization at the dimeric level, which facilitates cargo uptake and delivery. The structure displays heterogeneity revealing the dynamic nature of its C-terminal tail (CTT). Molecular dynamics (MD) simulations based on the CTDH structures identified specific residues that govern the dimeric transition mechanism. Mutagenesis based on the crystal structure and these MD simulations then confirmed that these specific residues within the CTT are critical for carotenoid uptake, encapsulation and delivery processes. We present a mechanism that can be applied to other systems that require cargo uptake.

PubMed: 32360310
DOI: 10.1016/j.bbabio.2020.148214

Experimental method

X-RAY DIFFRACTION (2.9 Å)