Single-residue insertion switches the quaternary structure and exciton states of cryptophyte light-harvesting proteins.

ABSTRACT: Observation of coherent oscillations in the 2D electronic spectra (2D ES) of photosynthetic proteins has led researchers to ask whether nontrivial quantum phenomena are biologically significant. Coherent oscillations have been reported for the soluble light-harvesting phycobiliprotein (PBP) antenna isolated from cryptophyte algae. To probe the link between spectral properties and protein structure, we determined crystal structures of three PBP light-harvesting complexes isolated from different species. Each PBP is a dimer of αβ subunits in which the structure of the αβ monomer is conserved. However, we discovered two dramatically distinct quaternary conformations, one of which is specific to the genus Hemiselmis. Because of steric effects emerging from the insertion of a single amino acid,

SUBMITTER: Harrop SJ 

PROVIDER: S-EPMC4084447 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature