Crystal structure of myoglobin from a synthetic gene.

Crystals have been grown of myoglobin produced in Escherichia coli from a synthetic gene, and the structure has been solved to 1.9 A resolution. The space group of the crystals is P6, which is different from previously solved myoglobin crystal forms. The synthetic myoglobin is essentially identical to myoglobin isolated from sperm whale tissue, except for the retention of the initiator methionine at the N-terminus and the substitution of asparagine for aspartic acid at position 122. Superposition of the coordinates of native and synthetic sperm whale myoglobins reveals only minor changes in the positions of main chain atoms and reorientation of some surface side chains. Crystals of variants of the "synthetic" myoglobin have also been grown for structural analysis of the role of key amino acid residues in ligand binding and specificity.