The 109 residue nerve tissue minihemoglobin from Cerebratulus lacteus highlights striking structural plasticity of the α-helical globin fold. Structure 2002

transport and storage [1–3], several novel Hb functions have recently emerged, including control of NO levels in microorganisms and dehaloperoxidase activity [4–7]. Despite the large variability in their primary and quater-nary structures, Hbs display a well-conserved tertiar