Figure 7.

Structure comparisons of the adrenodoxin–CYP11B2 fusion with adrenodoxin–CYP11A1 fusion and with the isolated CYP11B1 enzyme (PDB6M7X). Comparison of adrenodoxin–CYP11B2 fusion with adrenodoxin–CYP11A1 fusion highlights differences in the interactions with adrenodoxin α3 (A) and the P450 meander preceding the heme-coordinating loop (B). Comparison of the adrenodoxin–CYP11B2 fusion with the isolated CYP11B1 also identifies significant conformational differences in the meander (C). The meander region of the adrenodoxin–CYP11A1 fusion differs from that of adrenodoxin–CYP11B2 meander region (B) owing to multiple sequence differences, but this region of the isolated CYP11B1 (light pink) and adrenodoxin–CYP11B2 fusion (C) differ by a single amino acid residue at position 439 (Tyr in CYP11B1, His in CYP11B2). Adrenodoxin–CYP11B2: P450 domain, light blue and fused adrenodoxin domain, brown. Adrenodoxin–CYP11A1 P450 domain, light cyan and fused adrenodoxin domain, gray. CYP11B1 isolated structure, pink.