Biological Assembly 1  

Global Symmetry: Dihedral - D3  (3D View)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

Global Symmetry: Dihedral - D3  (3D View)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 677.87 kDa 
• Atom Count: 46,075 
• Modelled Residue Count: 5,568 
• Deposited Residue Count: 5,796 
• Unique protein chains: 1

 4FDH

Structure of human aldosterone synthase, CYP11B2, in complex with fadrozole

• PDB DOI: 10.2210/pdb4FDH/pdb

• Classification: OXIDOREDUCTASE/OXIDOREDUCTASE INHIBITOR
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2012-05-28 Released: 2013-01-30 
• Deposition Author(s): Strushkevich, N., Shen, L., Tempel, W., Arrowsmith, C., Edwards, A., Usanov, S.A., Park, H.-W.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.71 Å
• R-Value Free: 0.300 
• R-Value Work: 0.224 
• R-Value Observed: 0.228 

Literature

Structural insights into aldosterone synthase substrate specificity and targeted inhibition.

Strushkevich, N., Gilep, A.A., Shen, L., Arrowsmith, C.H., Edwards, A.M., Usanov, S.A., Park, H.W.

(2013) Mol Endocrinol 27: 315-324

• PubMed: 23322723 
• DOI: 10.1210/me.2012-1287
• Primary Citation of Related Structures:  
  4DVQ, 4FDH


• PubMed Abstract: 
  

Aldosterone is a major mineralocorticoid hormone that plays a key role in the regulation of electrolyte balance and blood pressure. Excess aldosterone levels can arise from dysregulation of the renin-angiotensin-aldosterone system and are implicated in the pathogenesis of hypertension and heart failure. Aldosterone synthase (cytochrome P450 11B2, CYP11B2) is the sole enzyme responsible for the production of aldosterone in humans. Blocking of aldosterone synthesis by mediating aldosterone synthase activity is thus a recently emerging pharmacological therapy for hypertension, yet a lack of structural information has limited this approach. Here, we present the crystal structures of human aldosterone synthase in complex with a substrate deoxycorticosterone and an inhibitor fadrozole. The structures reveal a hydrophobic cavity with specific features associated with corticosteroid recognition. The substrate binding mode, along with biochemical data, explains the high 11β-hydroxylase activity of aldosterone synthase toward both gluco- and mineralocorticoid formation. The low processivity of aldosterone synthase with a high extent of intermediates release might be one of the mechanisms of controlled aldosterone production from deoxycorticosterone. Although the active site pocket is lined by identical residues between CYP11B isoforms, most of the divergent residues that confer additional 18-oxidase activity of aldosterone synthase are located in the I-helix (vicinity of the O(2) activation path) and loops around the H-helix (affecting an egress channel closure required for retaining intermediates in the active site). This intrinsic flexibility is also reflected in isoform-selective inhibitor binding. Fadrozole binds to aldosterone synthase in the R-configuration, using part of the active site cavity pointing toward the egress channel. The structural organization of aldosterone synthase provides critical insights into the molecular mechanism of catalysis and enables rational design of more specific antihypertensive agents.

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Organizational Affiliation: 

Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada M5G 1L7. [e-mail]

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cytochrome P450 11B2, mitochondrial	A, B, C, D, E, F, G, H, I, J, K, L	483	Homo sapiens	Mutation(s): 0  Gene Names: Aldosterone synthase, CYP11B2 EC: 1.14.15.4 (PDB Primary Data), 1.14.15.5 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for P19099 (Homo sapiens) Explore P19099  Go to UniProtKB:  P19099
PHAROS:  P19099

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
HEM	AA [auth H], CA [auth I], EA [auth J], GA [auth K], IA [auth L], M [auth A], O [auth B], Q [auth C], S [auth D], U [auth E], W [auth F], Y [auth G]	PROTOPORPHYRIN IX CONTAINING FE C34 H32 Fe N4 O4 KABFMIBPWCXCRK-RGGAHWMASA-L
0T3	BA [auth H], DA [auth I], FA [auth J], HA [auth K], JA [auth L], N [auth A], P [auth B], R [auth C], T [auth D], V [auth E], X [auth F], Z [auth G]	4-[(5R)-5,6,7,8-tetrahydroimidazo[1,5-a]pyridin-5-yl]benzonitrile C14 H13 N3 CLPFFLWZZBQMAO-CQSZACIVSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
0T3	BindingDB:  4FDH	IC50: min: 0.8, max: 119 (nM) from 16 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.71 Å
• R-Value Free: 0.300 
• R-Value Work: 0.224 
• R-Value Observed: 0.228 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 129.751	α = 90
b = 199.086	β = 112.08
c = 150.018	γ = 90

Software Package:

Software Name	Purpose
SCALA	data scaling
REFMAC	refinement
PDB_EXTRACT	data extraction

Structure Validation

Entry History 

Deposition Data

• Released Date: 2013-01-30 
Deposition Author(s): Strushkevich, N., Shen, L., Tempel, W., Arrowsmith, C., Edwards, A., Usanov, S.A., Park, H.-W.

Revision History  

• Version 1.0: 2013-01-30
  Type: Initial release
  
• Version 1.1: 2013-02-13
  Changes: Database references