The first mutant of the Aequorea victoria GFP that forms a red chromophore reported.

Reference:
AS Mishin, FV Subach, IV Yampolsky, W King, KA Lukyanov, VV Verkhusha: The first mutant of the Aequorea victoria green fluorescent protein that forms a red chromophore. Biochemistry 47 (2008) 4666-73.