Patent ID: 7060793

Claim:
An isolated polypeptide comprising a circularly permuted Aequorea -related fluorescent protein moiety comprising: a linker moiety linking the amino-terminal and carboxy-terminal amino acids of a fluorescent protein, wherein the amino and carboxy termini are linked as internal amino acids in the circularly permuted Aequorea -related fluorescent protein moiety; and two terminal ends, wherein the first end is an amino-terminal end and the second end is a carboxy terminal end and wherein the amino and carboxy terminal ends of the circularly permuted Aequorea -related fluorescent protein moiety are different from the amino-terminal and carboxy-terminal amino acids of the fluorescent protein, wherein the amino acid residues of said fluorescent protein are numbered in conformance with native Aquorea green fluorescent protein (SEQ ID NO: 3) and wherein the first serine residue following methionine-1 in said fluorescent protein is designated amino acid residue 2, and wherein the amino-terminal end of the circularly permuted Aequorea -related fluorescent protein moiety is selected from the group consisting of E142, Y143, Y145, H148, D155, H169, E172, D173, A227 and I229, and the carboxy-terminal end of the circularly permuted Aequorea -related fluorescent protein moiety is selected from the group consisting of N144, N146, N149, K162, K156, N170, I171, D173, E172, A227, and I229, and wherein said circularly permuted fluorescent protein moiety comprises an optically active polypeptide capable of emitting light.