A cytochrome P450 monooxygenase that catalyzes the biosynthesis of adrenal mineralocorticoid aldosterone (PubMed:11856349, PubMed:23322723, PubMed:1594605, PubMed:9814506). Catalyzes three sequential oxidative reactions of 11-deoxycorticosterone/21-hydroxyprogesterone, namely 11-beta hydroxylation followed with two successive oxidations at C18 to yield 18-hydroxy and then 18-aldehyde derivatives, resulting in the formation of aldosterone (PubMed:11856349, PubMed:23322723, PubMed:1594605, PubMed:9814506). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate and reducing the second into a water molecule. Two electrons are provided by NADPH via a two-protein mitochondrial transfer system comprising flavoprotein FDXR (adrenodoxin/ferredoxin reductase) and nonheme iron-sulfur protein FDX1 or FDX2 (adrenodoxin/ferredoxin) (PubMed:11856349, PubMed:23322723, PubMed:1594605, PubMed:9814506). a steroid + 2 H(+) + O2 + 2 reduced [adrenodoxin] = an 11beta-hydroxysteroid + H2O + 2 oxidized [adrenodoxin] 21-hydroxyprogesterone + 2 H(+) + O2 + 2 reduced [adrenodoxin] = corticosterone + H2O + 2 oxidized [adrenodoxin] corticosterone + 2 H(+) + O2 + 2 reduced [adrenodoxin] = 18-hydroxycorticosterone + H2O + 2 oxidized [adrenodoxin] 18-hydroxycorticosterone + 2 H(+) + O2 + 2 reduced [adrenodoxin] = aldosterone + 2 H2O + 2 oxidized [adrenodoxin] 11-deoxycortisol + 2 H(+) + O2 + 2 reduced [adrenodoxin] = cortisol + H2O + 2 oxidized [adrenodoxin] Steroid biosynthesis. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. The molecular defect causing hyperaldosteronism familial 1 is an anti-Lepore-type fusion of the CYP11B1 and CYP11B2 genes. The hybrid gene has the promoting part of CYP11B1, ACTH-sensitive, and the coding part of CYP11B2. Belongs to the cytochrome P450 family. CYP11B2 entry