Among the wide variety of currently known fluorescent probes, photoconvertible fluorescent proteins (PCFPs), which are capable to irreversibly change their maximum of fluorescence emission under specific light irradiation, are of special interest. In this work, we have studied the basic physicochemical properties of PCFP isolated from Montastraea cavernosa (mcavGR). It has been shown that mcavGR demonstrates both high brightness and photoconversion contrast, which is comparable with the best homologous PCFPs, such as Kaede, dendFP, Dendra2, EosFP, etc., and at the same time has significant photostability.