N-m9Venus corresponds to an N-terminal portion (up to and including residue N144) of the Venus fluorescent protein that has been mutated to contain the amino acid replacement T153M (PMID:17959720). If the N-m9Venus split fluorescent fragment is brought together with a complementary split fluorescent fragment in vivo, a functional fluorescent protein may be reconstituted. N-m9Venus is designed for use in the bimolecular fluorescence complementation (BiFC) technique, in which a pair of complementary split fluorescent fragments is fused to interacting peptides to study protein-protein interactions in vivo (PMID:11983170).