title: Crystallization and preliminary X-ray characterization of the genetically encoded fluorescent calcium indicator protein GCaMP2.
abstract: Fluorescent proteins and their engineered variants have played an important role in the study of biology. The genetically encoded calcium-indicator protein GCaMP2 comprises a circularly permuted fluorescent protein coupled to the calcium-binding protein calmodulin and a calmodulin target peptide, M13, derived from the intracellular calmodulin target myosin light-chain kinase and has been used to image calcium transients in vivo. To aid rational efforts to engineer improved variants of GCaMP2, this protein was crystallized in the calcium-saturated form. X-ray diffraction data were collected to 2.0 A resolution. The crystals belong to space group C2, with unit-cell parameters a = 126.1, b = 47.1, c = 68.8 A, beta = 100.5 degrees and one GCaMP2 molecule in the asymmetric unit. The structure was phased by molecular replacement and refinement is currently under way.
authors.affiliation: Department of Biochemistry, University of Puerto Rico, Medical Sciences Campus, Puerto Rico.
authors.forename: María M
authors.initials: MM
authors.lastname: Rodríguez Guilbe
authors.forename: Elisa C
authors.initials: EC
authors.lastname: Alfaro Malavé
authors.forename: Jasper
authors.initials: J
authors.lastname: Akerboom
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Marvin
authors.forename: Loren L
authors.initials: LL
authors.lastname: Looger
authors.forename: Eric R
authors.initials: ER
authors.lastname: Schreiter
mesh_terms: D000595:Amino Acid Sequence; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000737:chemistry* / Q000235:genetics*; D003460:Crystallization; D049452:Green Fluorescent Proteins / Q000737:chemistry* / Q000235:genetics*; D007202:Indicators and Reagents; D008969:Molecular Sequence Data; D014961:X-Ray Diffraction
chemical_list: D007202:Indicators and Reagents; D049452:Green Fluorescent Proteins; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2