Haemopexin This is a 4-bladed beta-propeller protein. Each sheet has just 3 strands with a connection containing a short alpha-helix. The C- and N-termini are linked by a disulfide bond (red). Faber, H. R., Groom, C. R., Baker, H. M., Morgan, W. T., Smith, A., Baker, E. N.: 1.8 A crystal structure of the C-terminal domain of rabbit serum haemopexin. Structure 3 pp. 551 (1995) (PubMed) 1hxn (PDB)