- Crystallization and structure determination to 2.5-A resolution of the oxidized [2Fe-2S] ferredoxin isolated from Anabaena 7120. Rypniewski, W.R., Breiter, D.R., Benning, M.M., Wesenberg, G., Oh, B.H., Markley, J.L., Rayment, I., Holden, H.M. Biochemistry (1991)