Rossmann fold

Overview

An example of the Rossmann fold, a structural domain of a decarboxylase protein from the bacterium Staphylococcus epidermidis (PDB ID 1G5Q) with the bound flavin mononucleotide cofactor shown.

The Rossmann fold is a protein structural motif found in proteins that bind nucleotides, especially the cofactor NAD. 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.