6U2M

Crystal structure of a HaloTag-based calcium indicator, HaloCaMP V2, bound to JF635

Summary for 6U2M

• Entry DOI: 10.2210/pdb6u2m/pdb
• Descriptor: HaloCaMP V2, (1E,3S)-1-{10-[2-carboxy-5-({2-[2-(hexyloxy)ethoxy]ethyl}carbamoyl)phenyl]-7-(3-fluoroazetidin-1-yl)-5,5-dimethyldibenz o[b,e]silin-3(5H)-ylidene}-3-fluoroazetidin-1-ium, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: halotag, calcium, sensor, fluorescent, hydrolase
• Biological source: Rhodococcus sp.
• Total number of polymer chains: 2
• Total formula weight: 113499.40

Authors

Deo, C.,Schreiter, E.R. (deposition date: 2019-08-20, release date: 2020-09-30, Last modification date: 2023-10-11)

Primary citation

Deo, C.,Abdelfattah, A.S.,Bhargava, H.K.,Berro, A.J.,Falco, N.,Farrants, H.,Moeyaert, B.,Chupanova, M.,Lavis, L.D.,Schreiter, E.R.
The HaloTag as a general scaffold for far-red tunable chemigenetic indicators.
Nat.Chem.Biol., 17:718-723, 2021

PubMed Abstract: Functional imaging using fluorescent indicators has revolutionized biology, but additional sensor scaffolds are needed to access properties such as bright, far-red emission. Here, we introduce a new platform for 'chemigenetic' fluorescent indicators, utilizing the self-labeling HaloTag protein conjugated to environmentally sensitive synthetic fluorophores. We solve a crystal structure of HaloTag bound to a rhodamine dye ligand to guide engineering efforts to modulate the dye environment. We show that fusion of HaloTag with protein sensor domains that undergo conformational changes near the bound dye results in large and rapid changes in fluorescence output. This generalizable approach affords bright, far-red calcium and voltage sensors with highly tunable photophysical and chemical properties, which can reliably detect single action potentials in cultured neurons.

PubMed: 33795886
DOI: 10.1038/s41589-021-00775-w

Experimental method

X-RAY DIFFRACTION (2 Å)