TY - JOUR
T1 - Functional roles of tyrosine 185 during the bacteriorhodopsin photocycle as revealed by in situ spectroscopic studies
AU - Ding, Xiaoyan
AU - Sun, Chao
AU - Cui, Haolin
AU - Chen, Sijin
AU - Gao, Yujiao
AU - Yang, Yanan
AU - Wang, Juan
AU - He, Xiao
AU - Iuga, Dinu
AU - Tian, Fang
AU - Watts, Anthony
AU - Zhao, Xin
N1 - Funding Information:
This research was supported by grants to X.Z. from the National Natural Science Foundation of China (grant numbers 30970657 and 21475045 ), the Shanghai Pujiang Program (grant number 09PJ1404300 ), and the East China Normal University (grant numbers 79003A29 , 79301207 , 79301411 , and 41500-515430-14100 ) and by grants to A.W. from the Medical Research Council (grant number G1000909/1 ) and Engineering and Physical Sciences Research Council (grant number EP/1029516/1 ) of the UK and the State Administration of Foreign Experts Affairs of China through the High-End Foreign Experts Recruitment Program ( GDW20123100086 ) and by grant to F.T. from the National Institute of General Medical Sciences , National Institutes of Health (grant number R01GM105963 ). Access to the EPSRC 850 MHz NMR facility is also acknowledged.
PY - 2018/10
Y1 - 2018/10
N2 - Tyrosine 185 (Y185), one of the aromatic residues within the retinal (Ret) chromophore binding pocket in helix F of bacteriorhodopsin (bR), is highly conserved among the microbial rhodopsin family proteins. Many studies have investigated the functions of Y185, but its underlying mechanism during the bR photocycle remains unclear. To address this research gap, in situ two-dimensional (2D) magic-angle spinning (MAS) solid-state NMR (ssNMR) of specifically labelled bR, combined with light-induced transient absorption change measurements, dynamic light scattering (DLS) measurements, titration analysis and site-directed mutagenesis, was used to elucidate the functional roles of Y185 during the bR photocycle in the native membrane environment. Different interaction modes were identified between Y185 and the Ret chromophore in the dark-adapted (inactive) state and M (active) state, indicating that Y185 may serve as a rotamer switch maintaining the protein dynamics, and plays an important role in the efficient proton-pumping mechanism in the bR purple membrane.
AB - Tyrosine 185 (Y185), one of the aromatic residues within the retinal (Ret) chromophore binding pocket in helix F of bacteriorhodopsin (bR), is highly conserved among the microbial rhodopsin family proteins. Many studies have investigated the functions of Y185, but its underlying mechanism during the bR photocycle remains unclear. To address this research gap, in situ two-dimensional (2D) magic-angle spinning (MAS) solid-state NMR (ssNMR) of specifically labelled bR, combined with light-induced transient absorption change measurements, dynamic light scattering (DLS) measurements, titration analysis and site-directed mutagenesis, was used to elucidate the functional roles of Y185 during the bR photocycle in the native membrane environment. Different interaction modes were identified between Y185 and the Ret chromophore in the dark-adapted (inactive) state and M (active) state, indicating that Y185 may serve as a rotamer switch maintaining the protein dynamics, and plays an important role in the efficient proton-pumping mechanism in the bR purple membrane.
UR - http://www.scopus.com/inward/record.url?scp=85048461201&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048461201&partnerID=8YFLogxK
U2 - 10.1016/j.bbabio.2018.05.011
DO - 10.1016/j.bbabio.2018.05.011
M3 - Article
C2 - 29800547
AN - SCOPUS:85048461201
VL - 1859
SP - 1006
EP - 1014
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 10
ER -