Abstract
AbstractCryptophyte algae have a unique phycobiliprotein light-harvesting antenna that fills a spectral gap in chlorophyll absorption, however, it is unclear how it transfers energy efficiently to photosystems. We show that the cryptophyteHemiselmis anderseniiexpresses an energetically complex antenna comprising three distinct spectrotypes of phycobiliprotein with different quaternary structures arising from a diverse α subunit family. The bulk of the antenna consists ofopenquaternary form phycobiliproteins acting as primary photon acceptors, supplemented by novelopen-bracedforms. The final components areclosedforms with a long wavelength spectral feature due to substitution of a single chromophore. We propose that the macromolecular organization of the cryptophyte antennas consists of bulkopenandopen-bracedforms that transfer excitations to photosystems via this bridgingclosedform phycobiliprotein.One-Sentence SummaryAlgae generate a rainbow of antenna proteins by combining a conserved subunit with different members of a multigene family.
Publisher
Cold Spring Harbor Laboratory