7ZXV

Orange Carotenoid Protein Trp-288 BTA mutant

Summary for 7ZXV

• Entry DOI: 10.2210/pdb7zxv/pdb
• Descriptor: Orange carotenoid-binding protein, beta,beta-caroten-4-one, beta,beta-carotene-4,4'-dione, ... (5 entities in total)
• Functional Keywords: orange carotenoid protein, photoconversion, non-canonical amino acids, 3-benzothienyl-l-alanine, plant protein
• Biological source: Synechocystis sp. PCC 6803
• Total number of polymer chains: 1
• Total formula weight: 35852.81

Authors

Moldenhauer, M.,Tseng, H.-W.,Kraskov, A.,Tavraz, N.N.,Hildebrandt, P.,Hochberg, G.,Essen, L.-O.,Budisa, N.,Korf, L.,Maksimov, E.G.,Friedrich, T. (deposition date: 2022-05-23, release date: 2023-02-01, Last modification date: 2024-11-20)

Primary citation

Moldenhauer, M.,Tseng, H.W.,Kraskov, A.,Tavraz, N.N.,Yaroshevich, I.A.,Hildebrandt, P.,Sluchanko, N.N.,Hochberg, G.A.,Essen, L.O.,Budisa, N.,Korf, L.,Maksimov, E.G.,Friedrich, T.
Parameterization of a single H-bond in Orange Carotenoid Protein by atomic mutation reveals principles of evolutionary design of complex chemical photosystems.
Front Mol Biosci, 10:1072606-1072606, 2023

PubMed Abstract: Dissecting the intricate networks of covalent and non-covalent interactions that stabilize complex protein structures is notoriously difficult and requires subtle atomic-level exchanges to precisely affect local chemical functionality. The function of the Orange Carotenoid Protein (OCP), a light-driven photoswitch involved in cyanobacterial photoprotection, depends strongly on two H-bonds between the 4-ketolated xanthophyll cofactor and two highly conserved residues in the C-terminal domain (Trp288 and Tyr201). By orthogonal translation, we replaced Trp288 in OCP with 3-benzothienyl--alanine (BTA), thereby exchanging the imino nitrogen for a sulphur atom. Although the high-resolution (1.8 Å) crystal structure of the fully photoactive OCP-W288_BTA protein showed perfect isomorphism to the native structure, the spectroscopic and kinetic properties changed distinctly. We accurately parameterized the effects of the absence of a single H-bond on the spectroscopic and thermodynamic properties of OCP photoconversion and reveal general principles underlying the design of photoreceptors by natural evolution. Such "molecular surgery" is superior over trial-and-error methods in hypothesis-driven research of complex chemical systems.

PubMed: 36776742
DOI: 10.3389/fmolb.2023.1072606

Experimental method

X-RAY DIFFRACTION (1.8 Å)