NUMOD3 is a DNA-binding motif found in homing endonucleases and related proteins. It occurs on its own or in tandem repeats in GIY-YIG (Pfam:PF01541) and HTH proteins. It constitutes a beta-turn-loop-helix subregion of the the DNA-binding domain of I-TevI homing endonuclease (Swiss:P13299) [1].

1: New types of conserved sequence domains in DNA-binding regions of homing endonucleases. Sitbon E, Pietrokovski S; Trends Biochem Sci 2003;28:473-477. PMID:13678957