Sandbox Reserved 382: Difference between revisions

Due to the membrane-bound nature of mammalian cytochromes P450 (CYP), the structural characterization is extremely difficult. Aromatase is a monomeric enzyme composed of a heme-prosthetic group and a single polypeptide chain consisting of 503 amino-acid residues. <ref> Ghosh, D., Griswold, J., Erman, M., Pangborn, W. "X-ray Structure of Human Aromatase Reveals An Androgen Specific Active Site". [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826573/] </ref> One important feature of CYPs is the iron-containing porphyrin group at the enzyme active site. <ref> PMID: 16395678 </ref> Aromatase is anchored to the endoplasmic reticulum by the amino terminal transmembrane domain. The tertiary structure of Aromatase includes twelve major α-helices and ten β-strands<ref>Ghosh,D., Griswold,J., Erman,M., Pangborn, W. "X-ray Structure of Human Aromatase Reveals Androgen-Specific Active Site." [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2826573/] </ref>. An androstenedione molecule is bound to the active site of the enzyme. The active site of the enzyme can be found in the distal cavity of the heme-binding pocket. The <scene name='Sandbox_Reserved_382/Heme_iron/2'>heme iron</scene> is within the porphyrin and is considered the reaction center of the enzyme. The <scene name='Sandbox_Reserved_382/Ligand/1'>ligand (Cys437)</scene> is the region attached to the the porphyrin.

'''A ribbon diagram displaying the overall structure of the human placental aromatase is shown to the left.''' The amino terminus starts at residue 45 and is shown in dark blue. The carboxyl terminus ending at residue 496 is shown in red. The helices are labeled A-L and the sheets are labeled 1-10 accordingly. The heme group and the bound ligand are shown in the center of the protein.