C3PA-GFP encodes a photoactivatable derivative of the naturally occurring fluorescent protein encoded by the Aequorea victoria GFP gene (UniProtKB:P42212). It was identified in a screen for mutations of the canonical photoactivatable fluorophore PA-GFP with improved diffusional and folding properties, and incorporates three additional mutations (F99S, M153T and V163A) initially identified in the 'Cycle 3' mutant of GFP described in PMID:9630892. C3PA-GFP does not include the EGFP mutations F64L and S65T, which disrupt the ability to undergo photoactivation (FBrf0212443).