21-Hydroxylase
| Steroid 21-monooxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC number | 1.14.99.10 | ||||||||
| CAS number | 9029-68-9 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
21-Hydroxylase[edit | edit source]
Steroid 21-hydroxylase is an essential cytochrome P450 enzyme intricately involved in the biosynthesis of critical steroid hormones, namely aldosterone and cortisol. In humans, the genetic information for the synthesis of this enzyme is provided by the CYP21A2 gene.
Names and Classification[edit | edit source]
- Common Names: Steroid 21-monooxygenase, 21α-Hydroxylase.
- Alternate Name: 21β-Hydroxylase.
Function[edit | edit source]
Steroid 21-Hydroxylase belongs to the larger family of cytochrome P450 enzymes, a superfamily renowned for its role as monooxygenases. These enzymes participate in a variety of metabolic processes, including drug metabolism and the synthesis of vital molecules like cholesterol, steroids, and other lipids. Specifically, 21-Hydroxylase is found in the endoplasmic reticulum, where it hydroxylates steroids at the 21st carbon position. This enzymatic action is pivotal for the biosynthesis of steroid hormones, including cortisol and aldosterone.
Reaction Mechanism[edit | edit source]
21-Hydroxylase functions as a catalyst, facilitating the hydroxylation of the 21st carbon atom in steroid molecules, which translates to the addition of an "–OH" group. This modification is fundamental for the appropriate synthesis and function of certain hormones.
Steroid numbering - #21 is highlighted near center top.
Biosynthetic Pathway[edit | edit source]
The transformation catalyzed by 21-Hydroxylase is integral to several metabolic pathways, particularly those associated with steroid hormone synthesis.
 Human steroidogenesis, illustrating the two key reactions facilitated by 21-Hydroxylase, located centrally at the top. |
Clinical Relevance[edit | edit source]
Deficiencies or anomalies in the CYP21A2 gene can lead to compromised 21-Hydroxylase synthesis, which in turn results in congenital adrenal hyperplasia due to 21-hydroxylase deficiency. This condition can have significant clinical repercussions. Additionally, a pseudogene closely related to the CYP21A2 gene exists. gene conversion events between this pseudogene and the functional gene are considered the root cause for many instances of 21-hydroxylase deficiency.
External Resources[edit | edit source]
- GeneReviews/NCBI/NIH/UW article on 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia
- OMIM database entry on 21-Hydroxylase-Deficient Congenital Adrenal Hyperplasia
- Graphical Representation of Desoxycorticosterone Synthesis from Progesterone via 21-Hydroxylase
- Steroid+21-Hydroxylase at the US National Library of Medicine Medical Subject Headings (MeSH)
| 21-Hydroxylase Resources | ||
|---|---|---|
|
| |
Translate to: East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
Urdu,
বাংলা,
తెలుగు,
தமிழ்,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
European
español,
Deutsch,
français,
русский,
português do Brasil,
Italian,
polski
This concise article on 21-Hydroxylase incorporates public domain text from the US National Library of Medicine.
Navigation: Wellness - Encyclopedia - Health topics - Disease Index - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro) available.
Advertise on WikiMD
WikiMD is not a substitute for professional medical advice. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.
Contributors: Prab R. Tumpati, MD
