7ZVR

Crystal structure of the carotenoid-binding protein domain from silkworm Bombyx mori (BmCBP) complexed with zeaxanthin

Summary for 7ZVR

• Entry DOI: 10.2210/pdb7zvr/pdb
• Descriptor: Carotenoid-binding protein, (1R,2S)-4-{(1E,3E,5E,7E,9E,11E,13E,15E,17E)-18-[(4S)-4-hydroxy-2,6,6-trimethylcyclohex-1-en-1-yl]-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaen-1-yl}-2,5,5-trimethylcyclohex-3-en-1-ol (3 entities in total)
• Functional Keywords: carotenoid-binding protein, carotenoid transport, cbp, stard, start domain, bombyx mori, transport protein
• Biological source: Bombyx mori (domestic silkworm)
• Total number of polymer chains: 1
• Total formula weight: 29099.69

Authors

Sluchanko, N.N.,Boyko, K.M.,Varfolomeeva, L.A.,Slonimskiy, Y.B.,Egorkin, N.A.,Maksimov, E.G.,Popov, V.O. (deposition date: 2022-05-17, release date: 2022-10-26, Last modification date: 2024-01-31)

Primary citation

Sluchanko, N.N.,Slonimskiy, Y.B.,Egorkin, N.A.,Varfolomeeva, L.A.,Kleymenov, S.Y.,Minyaev, M.E.,Faletrov, Y.V.,Moysenovich, A.M.,Parshina, E.Y.,Friedrich, T.,Maksimov, E.G.,Boyko, K.M.,Popov, V.O.
Structural basis for the carotenoid binding and transport function of a START domain.
Structure, 30:1647-, 2022

PubMed Abstract: STARD3, a steroidogenic acute regulatory lipid transfer protein, was identified as a key xanthophyll-binding protein in the human retina. STARD3 and its homologs in invertebrates are known to bind and transport carotenoids, but this lacks structural elucidation. Here, we report high-resolution crystal structures of the apo- and zeaxanthin (ZEA)-bound carotenoid-binding protein from silkworm Bombyx mori (BmCBP). Having a STARD3-like fold, BmCBP features novel elements, including the Ω1-loop that, in the apoform, is uniquely fixed on the α4-helix by an R173-D279 salt bridge. We exploit absorbance, Raman and dichroism spectroscopy, and calorimetry to describe how ZEA and BmCBP mutually affect each other in the complex. We identify key carotenoid-binding residues, confirm their roles by ZEA-binding capacity and X-ray structures of BmCBP mutants, and also demonstrate that markedly different carotenoid-binding capacities of BmCBP and human STARD3 stem from differences in the structural organization of their carotenoid-binding cavity.

PubMed: 36356587
DOI: 10.1016/j.str.2022.10.007

Experimental method

X-RAY DIFFRACTION (2 Å)