Supporting information for Milani et al. (2003) Proc. Natl. Acad. Sci. USA, 10.1073/pnas.1037676100
Fig. 5. (A) Stereo view of a Fo- Fc map illustrating the occurrence of the TyrB10-23- TyrCD1-36 covalent bond in trHbO vertex subunits. The map has been calculated as follows: the trHbO refined model, devoid of any solvent molecules, was subjected to simulated annealing refinement (T = 2,500 K) and refinement, keeping zero occupancy for TyrB10 and TyrCD1. After convergence, one cycle of conventional restrained refinement was run and difference Fourier maps calculated. The highest-density feature resulting is the isodityrosine system, here displayed at a 3σ contour level. The model reported portrays the A subunit distal site region. (B) The heme distal site region, with electron density calculated as described in A, is reported here for the H subunit, a trHbO side subunit in the dodecamer, devoid of a covalent TyrB10-23- TyrCD1-36 bond.