Nitrous oxide reductases usually contain a seven-bladed beta-propeller domain with external short alpha-helices [1,2]. This entry represents a single blade of the propeller, with imperfect alpha-helix, usually at the C-terminus of the repeat region.

1: N2O binding at a [4Cu:2S] copper-sulphur cluster in nitrous oxide reductase. Pomowski A, Zumft WG, Kroneck PM, Einsle O; Nature. 2011;477:234-237. PMID:21841804

2: Role of Calcium in Secondary Structure Stabilization during Maturation of Nitrous Oxide Reductase. Schneider LK, Einsle O; Biochemistry. 2016;55:1433-1440. PMID:26885878