Structures of V45E and V45Y mutants and structure comparison of a variety of cytochrome b₅ mutants

The structures of cytochrome b₅ mutants V45E and V45Y reveal that the large side chains of Glu45 and Tyr45 of the mutants point to solvent instead of pointing to heme, leading to a decrease in the hydrophobicity of the heme pocket. The rotation of the porphyrin ring and the conformational change of the axial ligand His39 in the V45Y mutant indicate that the microenvironment of the heme is disturbed owing to the mutation.