The flavodoxin fold is a common ñ/ò protein fold, second only to the TIM barrel fold. It has three layers, with two ñ-helical layers sandwiching a 5-stranded parallel ò-sheet. The order of strands within the sheet is 2-1-3-4-5.
This motif is present for example in lactate dehydrogenase () or phosphoglycerate kinase ().