3EVU

Crystal structure of Calcium bound dimeric GCAMP2

Summary for 3EVU

• Entry DOI: 10.2210/pdb3evu/pdb
• Related: 3EVP 3EVR 3EVV
• Descriptor: Myosin light chain kinase, Green fluorescent protein, Calmodulin-1 chimera, CALCIUM ION (3 entities in total)
• Functional Keywords: gcamp2, calcium sensor, gfp, calmodulin, m13, signaling protein
• Biological source: Aequorea victoria (Jellyfish); More
• Cellular location: Cytoplasm, cytoskeleton, spindle: P0DP29
• Total number of polymer chains: 1
• Total formula weight: 50864.90

Authors

Wang, Q.,Shui, B.,Kotlikoff, M.I.,Sondermann, H. (deposition date: 2008-10-13, release date: 2008-12-09, Last modification date: 2023-12-27)

Primary citation

Wang, Q.,Shui, B.,Kotlikoff, M.I.,Sondermann, H.
Structural Basis for Calcium Sensing by GCaMP2.
Structure, 16:1817-1827, 2008

PubMed Abstract: Genetically encoded Ca(2+) indicators are important tools that enable the measurement of Ca(2+) dynamics in a physiologically relevant context. GCaMP2, one of the most robust indicators, is a circularly permutated EGFP (cpEGFP)/M13/calmodulin (CaM) fusion protein that has been successfully used for studying Ca(2+) fluxes in vivo in the heart and vasculature of transgenic mice. Here we describe crystal structures of bright and dim states of GCaMP2 that reveal a sophisticated molecular mechanism for Ca(2+) sensing. In the bright state, CaM stabilizes the fluorophore in an ionized state similar to that observed in EGFP. Mutational analysis confirmed critical interactions between the fluorophore and elements of the fused peptides. Solution scattering studies indicate that the Ca(2+)-free form of GCaMP2 is a compact, predocked state, suggesting a molecular basis for the relatively rapid signaling kinetics reported for this indicator. These studies provide a structural basis for the rational design of improved Ca(2+)-sensitive probes.

PubMed: 19081058
DOI: 10.1016/j.str.2008.10.008

Experimental method

X-RAY DIFFRACTION (1.75 Å)