Hemoglobin San Diego (beta 109 (G11) val--met). Crystal structure of the deoxy form.

The three-dimensional structure of deoxyhemoglobin San Diego has been solved to 3.5 A resolution using mixed crystals of the variant hemoglobin and hemoglobin A. The site of the amino acid replacement can be clearly located in the difference electron density map and is consistent with the chemical result (beta109 Val-->Met) discussed in the preceding paper. The abnormally high oxygen affinity and impaired cooperativity appear to result from perturbations of the alpha(1)beta(1)-subunit interface.