title: The 2.0-A crystal structure of eqFP611, a far red fluorescent protein from the sea anemone Entacmaea quadricolor.
abstract: We have crystallized and subsequently determined to 2.0-A resolution the crystal structure of eqFP611, a far red fluorescent protein from the sea anemone Entacmaea quadricolor. The structure of the protomer, which adopts a beta-can topology, is similar to that of the related monomeric green fluorescent protein (GFP). The quaternary structure of eqFP611, a tetramer exhibiting 222 symmetry, is similar to that observed for the more closely related red fluorescent protein DsRed and the chromoprotein Rtms5. The unique chromophore sequence (Met63-Tyr64-Gly65) of eqFP611, adopts a coplanar and trans conformation within the interior of the beta-can fold. Accordingly, the eqFP611 chromophore adopts a significantly different conformation in comparison to the chromophore conformation observed in GFP, DsRed, and Rtms5. The coplanar chromophore conformation and its immediate environment provide a structural basis for the far red, highly fluorescent nature of eqFP611. The eqFP611 structure extends our knowledge on the range of conformations a chromophore can adopt within closely related members of the green fluorescent protein family.
authors.affiliation: The Protein Crystallography Unit, School of Biomedical Sciences, Monash University, Victoria, Australia.
authors.forename: Jan
authors.initials: J
authors.lastname: Petersen
authors.forename: Pascal G
authors.initials: PG
authors.lastname: Wilmann
authors.forename: Travis
authors.initials: T
authors.lastname: Beddoe
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Oakley
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Devenish
authors.forename: Mark
authors.initials: M
authors.lastname: Prescott
authors.forename: Jamie
authors.initials: J
authors.lastname: Rossjohn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray; D049452:Green Fluorescent Proteins; D006860:Hydrogen Bonding; D008164:Luminescent Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D012615:Sea Anemones / Q000737:chemistry*; D000097573:Red Fluorescent Protein
chemical_list: D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein