Glu46 donates a proton to the 4-hydroxycinnamate anion chromophore during the photocycle of photoactive yellow protein

被引:173
作者
Xie, AH
Hoff, WD
Kroon, AR
Hellingwerf, KJ
机构
[1] UNIV TEXAS,SCH MED,HLTH SCI CTR,DEPT MICROBIOL & MOL GENET,HOUSTON,TX 77030
[2] UNIV AMSTERDAM,EC SLATER INST BIOCHEM RES,DEPT MICROBIOL,NL-1018 WS AMSTERDAM,NETHERLANDS
关键词
D O I
10.1021/bi9623035
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Photoactive yellow protein (PYP) is a photoreceptor containing a unique 4-hydroxycinnamic acid (pCA) chromophore. The trans to cis photoisomerization of this chromophore activates a photocycle involving first a short-lived red-shifted intermediate (pR), then a long-lived blue-shifted intermediate (pB), and finally recovery of the original receptor state (pG). The pCA chromophore is deprotonated in pG and protonated in pB, but the proton donor for this process has not yet been identified. Here we report the first FTIR spectroscopic data on pc, pR, and pB. The IR difference signals in the carbonyl stretching region of COOH groups (1700-1800 cm(-1)) reveal that a buried carboxylic group close to the chromophore (i) is protonated in pG, (ii) develops a stronger hydrogen bonding in pR, and (iii) becomes deprotonated in pB. These signals are unambiguously assigned to Glu46, on the basis of the IR data and the 1.4 Angstrom X-ray structure of PYP [Borgstahl et al. (1995) Biochemistry 34, 6278-6287]. Our data demonstrate that in pR Glu46 remains in hydrogen bonding contact with the negatively charged phenolic oxygen of pCA after chromophore photoisomerization. This strongly implies that the chromophore is isomerized to the 7-cis 9-s-trans conformation in pR, resulting from co-isomerization of both the C-7=C-8 and C-9-C-10 bands. In the pR to pB transition, Glu46 becomes deprotonated, concomitant with chromophore protonation, Therefore, we conclude that Glu46 functions as the proton donor for the protonation of PCA during the PYP photocycle. We propose a molecular mechanism in which intramolecular proton transfer in PYP leads to global protein conformational changes involved in signal transduction.
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收藏
页码:14671 / 14678
页数:8
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共 34 条
[11]   GLASSY BEHAVIOR OF A PROTEIN [J].
IBEN, IET ;
BRAUNSTEIN, D ;
DOSTER, W ;
FRAUENFELDER, H ;
HONG, MK ;
JOHNSON, JB ;
LUCK, S ;
ORMOS, P ;
SCHULTE, A ;
STEINBACH, PJ ;
XIE, AH ;
YOUNG, RD .
PHYSICAL REVIEW LETTERS, 1989, 62 (16) :1916-1919
[12]   RESONANCE RAMAN EVIDENCE THAT THE THIOESTER-LINKED 4-HYDROXYCINNAMYL CHROMOPHORE OF PHOTOACTIVE YELLOW PROTEIN IS DEPROTONATED [J].
KIM, M ;
MATHIES, RA ;
HOFF, WD ;
HELLINGWERF, KJ .
BIOCHEMISTRY, 1995, 34 (39) :12669-12672
[13]   Sequence evidence for strong conservation of the photoactive yellow proteins from the halophilic phototrophic bacteria Chromatium salexigens and Rhodospirillum salexigens [J].
Koh, M ;
VanDriessche, G ;
Samyn, B ;
Hoff, WD ;
Meyer, TE ;
Cusanovich, MA ;
VanBeeumen, JJ .
BIOCHEMISTRY, 1996, 35 (08) :2526-2534
[14]   Evidence for trans-cis isomerization of the p-coumaric acid chromophore as the photochemical basis of the photocycle of photoactive yellow protein [J].
Kort, R ;
Vonk, H ;
Xu, X ;
Hoff, WD ;
Crielaard, W ;
Hellingwerf, KJ .
FEBS LETTERS, 1996, 382 (1-2) :73-78
[15]   The xanthopsins: A new family of eubacterial blue-light photoreceptors [J].
Kort, R ;
Hoff, WD ;
VanWest, M ;
Kroon, AR ;
Hoffer, SM ;
Vlieg, KH ;
Crielaard, W ;
VanBeeumen, JJ ;
Hellingwerf, KJ .
EMBO JOURNAL, 1996, 15 (13) :3209-3218
[16]  
KROON AR, 1996, IN PRESS J BIOL CHEM
[17]  
Maeda A, 1995, ISR J CHEM, V35, P387
[18]   PHOTOACTIVE YELLOW PROTEIN FROM THE PURPLE PHOTOTROPHIC BACTERIUM, ECTOTHIORHODOSPIRA-HALOPHILA - QUANTUM YIELD OF PHOTOBLEACHING AND EFFECTS OF TEMPERATURE, ALCOHOLS, GLYCEROL, AND SUCROSE ON KINETICS OF PHOTOBLEACHING AND RECOVER [J].
MEYER, TE ;
TOLLIN, G ;
HAZZARD, JH ;
CUSANOVICH, MA .
BIOPHYSICAL JOURNAL, 1989, 56 (03) :559-564
[19]   TRANSIENT PROTON UPTAKE AND RELEASE IS ASSOCIATED WITH THE PHOTOCYCLE OF THE PHOTOACTIVE YELLOW PROTEIN FROM THE PURPLE PHOTOTROPHIC BACTERIUM ECTOTHIORHODOSPIRA-HALOPHILA [J].
MEYER, TE ;
CUSANOVICH, MA ;
TOLLIN, G .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1993, 306 (02) :515-517
[20]   PROPERTIES OF A WATER-SOLUBLE, YELLOW PROTEIN ISOLATED FROM A HALOPHILIC PHOTOTROPHIC BACTERIUM THAT HAS PHOTOCHEMICAL ACTIVITY ANALOGOUS TO SENSORY RHODOPSIN [J].
MEYER, TE ;
YAKALI, E ;
CUSANOVICH, MA ;
TOLLIN, G .
BIOCHEMISTRY, 1987, 26 (02) :418-423