The present invention provides variants of fluorescent proteins, which are improved with regard to their properties for use as reporter proteins and/or in analytics. In particular, variants of fluorescent proteins are provided, which fluoresce brighter, show improved quantum yield and/or have shifted excitation or emission spectra. The fluorescent proteins according to the invention comprise in their LOV domain besides the substitution of a cysteine with an amino acid that does not covalently bind FMN at least one further point mutation.
