Hoff W D, Düx P, Hård K, Devreese B, Nugteren-Roodzant I M, Crielaard W, Boelens R, Kaptein R, van Beeumen J, Hellingwerf K J
Department of Microbiology, E. C. Slater Institute, University of Amsterdam, The Netherlands.
Biochemistry. 1994 Nov 29;33(47):13959-62. doi: 10.1021/bi00251a001.
A number of Eubacteria contain a photoactive yellow protein which has a photosensory function in negative phototaxis. It has been proposed that the cofactor responsible for the intense yellow color of this protein is retinal [McRee, D. E., et al. (1989) Proc. Natl. Acad. Sci. U.S.A. 86, 6533-6537]. This would make it the first eubacterial rhodopsin. Here we report the chemical structure of this chromophoric group to be p-coumaric acid, which is covalently bound to a unique cysteine in the apoprotein via a thiol ester bond, and thus not retinal. This makes PYP the first example of a protein containing p-coumaric acid, a metabolite previously found only in plants, as a prosthetic group and establishes the photoactive yellow proteins as a new type of photochemically active receptor molecule.
许多真细菌含有一种光活性黄色蛋白，该蛋白在负趋光性中具有光感功能。有人提出，负责该蛋白强烈黄色的辅因子是视黄醛[麦克里，D. E.等人（1989年）《美国国家科学院院刊》86卷，6533 - 6537页]。这将使其成为首个真细菌视紫红质。在此我们报告，这种发色团的化学结构为对香豆酸，它通过硫酯键与脱辅基蛋白中一个独特的半胱氨酸共价结合，因而不是视黄醛。这使得PYP成为首个含有对香豆酸（一种此前仅在植物中发现的代谢产物）作为辅基的蛋白实例，并将光活性黄色蛋白确立为一种新型的光化学活性受体分子。
