罗斯曼折叠（英语：Rossmann fold）是一种蛋白质结构基序，常见于核苷酸结合蛋白质，特别是辅因子NAD结合蛋白。该结构由两个重复的部分组成，每个部分包括6个平行的β折叠与两对α螺旋形成β-α-β-α-β的拓扑结构。因为每一个罗斯曼折叠可以和一个核苷酸结合，像NAD等二核苷酸的结合域包括二个成对的罗斯曼折叠，分别和辅因子的一个核苷酸部份结合。单一的罗斯曼折叠可以和单核苷酸结合，例如辅因子FMN。

该结构以迈克尔·罗斯曼命名，因其第一个发现这种多见于核苷酸结合蛋白（比如一些脱氢酶）的折叠结构。

The Rossmann fold is a protein structural motif found in proteins that bind nucleotides, such as enzyme cofactors FAD, NAD, and NADP. The structure is composed of up to seven mostly parallel beta strands. The first two strands are connected by an α- helix. The structures of segments between additional strands vary greatly and may include structures such as short helical segments and coils.