We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Structure, function and evolution of the cyanobacterial orange carotenoid protein and its homologs.
- Authors
Kerfeld, Cheryl A.; Melnicki, Matthew R.; Sutter, Markus; Dominguez‐Martin, Maria Agustina
- Abstract
Contents937I.937II.938III.939IV.943V.947VI.948948References949 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, OCPO, to a red form, OCPR. 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 (OCP1, OCP2, OCPX). The fluorescence recovery protein (FRP) detaches OCP1 from the PBS core, accelerating its back‐conversion to OCPO; by contrast, other OCP families are not regulated by FRP. N‐terminal domain homologs, the helical carotenoid proteins (HCPs), have been found among diverse cyanobacteria, occurring as multiple paralogous groups, with two representatives exhibiting strong singlet oxygen (1O2) quenching (HCP2, HCP3) and another capable of dissipating PBS excitation (HCP4). Crystal structures are presently available for OCP1 and HCP1, 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 1O2 quenching.
- Subjects
BACTERIAL proteins; ENERGY dissipation; PHYCOBILISOMES; CYANOBACTERIA; PHOTOACTIVATION; CRYSTAL structure; PHOTOACTIVE yellow protein
- Publication
New Phytologist, 2017, Vol 215, Issue 3, p937
- ISSN
0028-646X
- Publication type
Article
- DOI
10.1111/nph.14670