6MHI

Photoactive Yellow Protein with covalently bound 3,5-dichloro-4-hydroxycinnamic acid chromophore

6MHI の概要

• エントリーDOI: 10.2210/pdb6mhi/pdb
• 分子名称: Photoactive yellow protein, (2E)-3-(3,5-dichloro-4-hydroxyphenyl)prop-2-enoic acid (3 entities in total)
• 機能のキーワード: chlorinated chromophore, hydrogen bonding network, active site, low-barrier hydrogen bond, signaling protein
• 由来する生物種: Halorhodospira halophila
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 14121.62

構造登録者

Thomson, B.D.,Both, J.,Wu, Y.,Parrish, R.M.,Martinez, T.,Boxer, S.G. (登録日: 2018-09-18, 公開日: 2019-05-29, 最終更新日: 2024-11-20)

主引用文献

Thomson, B.,Both, J.,Wu, Y.,Parrish, R.M.,Martinez, T.J.,Boxer, S.G.
Perturbation of Short Hydrogen Bonds in Photoactive Yellow Protein via Noncanonical Amino Acid Incorporation.
J.Phys.Chem.B, 123:4844-4849, 2019

PubMed Abstract: Photoactive yellow protein (PYP) is a small photoreceptor protein that has two unusually short hydrogen bonds between the deprotonated p-coumaric acid chromophore and two amino acids, a tyrosine and a glutamic acid. This has led to considerable debate as to whether the glutamic acid-chromophore hydrogen bond is a low barrier hydrogen bond, with conflicting results in the literature. We have modified the p K of the tyrosine by amber suppression and of the chromophore by chemical substitution. X-ray crystal structures of these modified proteins are nearly identical to the wild-type protein, so the heavy atom distance between proton donor and acceptor is maintained, even though these modifications change the relative proton affinity between donor and acceptor. Despite a considerable change in relative proton affinity, the NMR chemical shifts of the hydrogen-bonded protons are only moderately affected. QM/MM calculations were used to explore the protons' potential energy surface and connect the calculated proton position with empirically measured proton chemical shifts. The results are inconsistent with a low barrier hydrogen bond but in all cases are consistent with a localized proton, suggesting an ionic hydrogen bond rather than a low barrier hydrogen bond.

PubMed: 31117606
DOI: 10.1021/acs.jpcb.9b01571

実験手法

X-RAY DIFFRACTION (1.35 Å)