TY - JOUR
T1 - A Molecular Mechanism for Nonphotochemical Quenching in Cyanobacteria
AU - Lu, Yue
AU - Liu, Haijun
AU - Saer, Rafael
AU - Li, Veronica L.
AU - Zhang, Hao
AU - Shi, Liuqing
AU - Goodson, Carrie
AU - Gross, Michael L.
AU - Blankenship, Robert E.
N1 - Funding Information:
This research was funded by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Photosynthetic Systems (PS) Program (Grant DE-FG02-07ER15902 to R.E.B.). Mass spectrometry instrumentation was made available by the Photosynthetic Antenna Research Center (PARC), an Energy Frontier Research Center funded by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences (Grant DE-SC0001035). Partial support was also provided by the National Institute of General Medical Sciences of the National Institutes of Health (Grant 2P41GM103422 to M.L.G.). The DOE PS grant and NIH grant each provided partial support for Y.L.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/6/6
Y1 - 2017/6/6
N2 - The cyanobacterial orange carotenoid protein (OCP) protects photosynthetic cyanobacteria from photodamage by dissipating excess excitation energy collected by phycobilisomes (PBS) as heat. Dissociation of the PBS-OCP complex in vivo is facilitated by another protein known as the fluorescence recovery protein (FRP), which primarily exists as a dimeric complex. We used various mass spectrometry (MS)-based techniques to investigate the molecular mechanism of this FRP-mediated process. FRP in the dimeric state (dFRP) retains its high affinity for the C-terminal domain (CTD) of OCP in the red state (OCPr). Site-directed mutagenesis and native MS suggest the head region on FRP is a candidate to bind OCP. After attachment to the CTD, the conformational changes of dFRP allow it to bridge the two domains, facilitating the reversion of OCPr into the orange state (OCPo) accompanied by a structural rearrangement of dFRP. Interestingly, we found a mutual response between FRP and OCP; that is, FRP and OCPr destabilize each other, whereas FRP and OCPo stabilize each other. A detailed mechanism of FRP function is proposed on the basis of the experimental results.
AB - The cyanobacterial orange carotenoid protein (OCP) protects photosynthetic cyanobacteria from photodamage by dissipating excess excitation energy collected by phycobilisomes (PBS) as heat. Dissociation of the PBS-OCP complex in vivo is facilitated by another protein known as the fluorescence recovery protein (FRP), which primarily exists as a dimeric complex. We used various mass spectrometry (MS)-based techniques to investigate the molecular mechanism of this FRP-mediated process. FRP in the dimeric state (dFRP) retains its high affinity for the C-terminal domain (CTD) of OCP in the red state (OCPr). Site-directed mutagenesis and native MS suggest the head region on FRP is a candidate to bind OCP. After attachment to the CTD, the conformational changes of dFRP allow it to bridge the two domains, facilitating the reversion of OCPr into the orange state (OCPo) accompanied by a structural rearrangement of dFRP. Interestingly, we found a mutual response between FRP and OCP; that is, FRP and OCPr destabilize each other, whereas FRP and OCPo stabilize each other. A detailed mechanism of FRP function is proposed on the basis of the experimental results.
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U2 - 10.1021/acs.biochem.7b00202
DO - 10.1021/acs.biochem.7b00202
M3 - Article
C2 - 28513152
AN - SCOPUS:85020248525
SN - 0006-2960
VL - 56
SP - 2812
EP - 2823
JO - Biochemistry
JF - Biochemistry
IS - 22
ER -