The Rossmann fold is a proteinstructural motif found in proteins that bind nucleotides, especially the cofactorNAD. The structure is composed of three or more parallel beta strands linked by two alpha helices in the topological order beta-alpha-beta-alpha-beta. Because each Rossmann fold can bind one nucleotide, binding domains for dinucleotides such as NAD consist of two paired Rossmann folds that each bind one nucleotide moiety of the cofactor molecule. Single Rossmann folds can bind mononucleotides such as the cofactor FMN.
The motif is named for Michael Rossmann who first pointed out that this was a frequently occurring motif in nucleotide binding proteins.[1]