[Structural organization and localization of cytochromes P450 in the membrane].
The secondary structure prediction of 19 microsomal cytochrome P-450s from two different families was made based on their amino acid sequences. It was shown that there is a structural similarity between the heme-binding sites of these enzymes and the bacterial P-450cam. An average predicted secondary structure of cytochrome P-450 proteins with 70% accuracy contains about 46% alpha-helices, 12% beta-strands, 9% beta-turns and 33% random coil. In the region of the 35-120 residues in microsomal P-450s two adjacent beta alpha beta-units (the Rossmann domain) were recognized, which may interact with the NADPH-cytochrome P-450 reductase. Using the procedure of identification of hydrophobic and membrane-associated alpha-helical segments of 23 cytochromes, only one N-terminal transmembrane anchor was predicted. Also the heme-binding site perhaps includes surface-bound helix. A model of vertebrate microsomal P-450s is proposed. That is an amphypathic membrane protein located on the cytoplasmic face of the endoplasmic reticulum, their active center lies out/on the bilayer border.
Tret'iakov
V E
VE
Degtiarenko
K N
KN
Uvarov
V Iu
VIu
Archakov
A I
AI
Tret'iakova
L Z
LZ
Varenitsa
A I
AI
D000595:Amino Acid Sequence; D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000235:genetics*; D006801:Humans; D007425:Intracellular Membranes / Q000201:enzymology*; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics; D008861:Microsomes / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D051381:Rats; D012689:Sequence Homology, Nucleic Acid
D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System
Strukturnaia organizatsiia i raspolozhenie tsitokhromov P450 v membrane.