Structure, function and evolution of the cyanobacterial orange carotenoid protein and its homologs

Journal Article · 04 July 2017 · New Phytologist

DOI: https://doi.org/10.1111/nph.14670 · OSTI ID:1596267

Kerfeld, Cheryl A.  ^[1]; Melnicki, Matthew R. ^[2]; Sutter, Markus ^[2]; Dominguez-Martin, Maria Agustina ^[3]

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1. MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing MI 48824 USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing MI 48824 USA
2. MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing MI 48824 USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720 USA
3. MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing MI 48824 USA

Contents Summary 937 I. Introduction 937 II. The structure of the OCP 938 III. OCP function 939 IV. Distribution of OCPs, FRP and domains in cyanobacteria 943 V. Carotenoid–protein interactions in the OCP and the HCPs 947 VI. Conclusions and prospects 948 Acknowledgements 948 References 949 Summary The orange carotenoid protein ( OCP ) is a water‐soluble, photoactive protein involved in thermal dissipation of excess energy absorbed by the light‐harvesting phycobilisomes ( PBS ) in cyanobacteria. The OCP is structurally and functionally modular, consisting of a sensor domain, an effector domain and a keto‐carotenoid. On photoactivation, the OCP converts from a stable orange form, OCP ^O , to a red form, OCP ^R . Activation is accompanied by a translocation of the carotenoid deeper into the effector domain. The increasing availability of cyanobacterial genomes has enabled the identification of new OCP families ( OCP 1, OCP 2, OCPX ). The fluorescence recovery protein ( FRP ) detaches OCP 1 from the PBS core, accelerating its back‐conversion to OCP ^O ; by contrast, other OCP families are not regulated by FRP . N‐terminal domain homologs, the helical carotenoid proteins ( HCP s), have been found among diverse cyanobacteria, occurring as multiple paralogous groups, with two representatives exhibiting strong singlet oxygen ( ¹ O ₂ ) quenching ( HCP 2, HCP 3) and another capable of dissipating PBS excitation ( HCP 4). Crystal structures are presently available for OCP 1 and HCP 1, and models of other HCP subtypes can be readily produced as a result of strong sequence conservation, providing new insights into the determinants of carotenoid binding and ¹ O ₂ quenching.

• Research Organization: Michigan State Univ., East Lansing, MI (United States). MSU-DOE Plant Research Laboratory
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE
• Grant/Contract Number: FG02-91ER20021; DE‐FG02‐91ER20021
• OSTI ID: 1596267
• Alternate ID(s): OSTI ID: 1401906
• Journal Information: New Phytologist, Vol. 215, Issue 3; ISSN 0028-646X
• Publisher: WileyCopyright Statement
• Country of Publication: United States
• Language: English