Rossmannfold

Rossmannfold is a term used in structural biology to describe a class or subtype of nucleotide-binding protein folds closely related to the canonical Rossmann fold. In typical descriptions, a Rossmannfold features a central beta sheet flanked by alpha helices, forming a pocket that accommodates dinucleotide cofactors such as NAD+, NADP+, or FAD. This arrangement supports a range of redox and other chemical transformations by facilitating dinucleotide binding and proper orientation of catalytic residues.

The fold is observed in diverse enzymes from bacteria, archaea, and eukaryotes, including dehydrogenases, oxidoreductases, and some epimerases. Variants of the Rossmannfold may differ in the exact topology of the beta strands or the length and conformation of connecting loops, leading to differences in cofactor preference and substrate specificity. Functional studies often relate subtle topological differences to shifts in catalytic mechanism or regulation.

Nomenclature and interpretation: The term Rossmannfold is not standardized across the literature. Some authors use it as a near-synonym for the canonical Rossmann fold, while others reserve it for a doughnut-shaped or slightly rearranged topology within the broader fold family. The name pays homage to Michael Rossmann, whose work established the principle of nucleotide-binding folds.

See also: Rossmann fold.