Red, Cryptomonad and Glaucocystophyte Algal Phycobiliproteins

Abstract

A significant amount of research has been done on phycobiliproteins over the past ten years. A much fuller description ofthe cryptomonad bilins has expanded the number ofknown chromophores in phycobiliproteins. A number of new phycobiliproteins have been identified from red algal strains. Comparative genomics has become possible with the sequencing of the vast majority of phycobiliprotein and linker polypeptides in Cyanobacteria and in red, glaucocystophyte and cryptomonad algae. Structural studies have elucidated most of the major phycobiliprotein subunits and now some of the linker polypeptides to more fully understand the energy transfer within phycobiliproteins. While the majority of the research still focuses on cyanobacterial systems, red and cryptomonad algal phycobiliproteins enjoyed a renewed emphasis during this decade. The glaucocystophytes have also been studied, as much for their significance for plastid evolution as for their phycobiliprotein structure and function, which is very much like that in Cyanobacteria. Most ofthe research on these eukaryotic organisms focused on crystal structure and gene comparisons to cyanobacterial systems, with a liberal amount ofnew methodology for phycobiliprotein isolation from red algal strains thrown in. The focus has mostly been on comparison ofthe red and cryptomonad algal systems to what has been demonstrated in cyanobacterial systems when it comes to structure/function relationships. The lack ofuseful genetic systems in red and cryptomonad algae is a current major inhibitor of direct structure/function studies in the red and cryptomonad algal systems; allowing cyanobacterial research to take the lead so far.