title: Thiol ester-linked p-coumaric acid as a new photoactive prosthetic group in a protein with rhodopsin-like photochemistry.
abstract: 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.
authors.affiliation: Department of Microbiology, E. C. Slater Institute, University of Amsterdam, The Netherlands.
authors.forename: W D
authors.initials: WD
authors.lastname: Hoff
authors.forename: P
authors.initials: P
authors.lastname: Düx
authors.forename: K
authors.initials: K
authors.lastname: Hård
authors.forename: B
authors.initials: B
authors.lastname: Devreese
authors.forename: I M
authors.initials: IM
authors.lastname: Nugteren-Roodzant
authors.forename: W
authors.initials: W
authors.lastname: Crielaard
authors.forename: R
authors.initials: R
authors.lastname: Boelens
authors.forename: R
authors.initials: R
authors.lastname: Kaptein
authors.forename: J
authors.initials: J
authors.lastname: van Beeumen
authors.forename: K J
authors.initials: KJ
authors.lastname: Hellingwerf
mesh_terms: D002841:Chromatiaceae / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D004229:Dithiothreitol / Q000494:pharmacology; D004952:Esters / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D011422:Propionates; D012243:Rhodopsin / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000494:pharmacology; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D003373:Coumaric Acids; D004220:Disulfides; D004952:Esters; D011422:Propionates; D013438:Sulfhydryl Compounds; D012972:Sodium Hydroxide; D012243:Rhodopsin; C495469:p-coumaric acid; D003545:Cysteine; D004229:Dithiothreitol