Figure 9. Comparison of cytochrome c1 and hinge protein from the orthorhombic crystals of chicken bc₁ (1bcc) with that from the p6₅22 bovine enzyme (1be3). The bovine structure is on the left, the chicken on the right. A significant difference (described in the text) is indicated by the gray arrow. Because this area has poor order in both structures, the difference could be due to mis-tracing the polypeptide chain as well as to crystal packing or species differences.