4NKY

Human steroidogenic cytochrome P450 17A1 mutant A105L with substrate 17alpha-hydroxyprogesterone


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.178 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structures of Human Steroidogenic Cytochrome P450 17A1 with Substrates.

Petrunak, E.M.DeVore, N.M.Porubsky, P.R.Scott, E.E.

(2014) J.Biol.Chem. 289: 32952-32964

  • DOI: 10.1074/jbc.M114.610998
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The human cytochrome P450 17A1 (CYP17A1) enzyme operates at a key juncture of human steroidogenesis, controlling the levels of mineralocorticoids influencing blood pressure, glucocorticoids involved in immune and stress responses, and androgens and e ...

    The human cytochrome P450 17A1 (CYP17A1) enzyme operates at a key juncture of human steroidogenesis, controlling the levels of mineralocorticoids influencing blood pressure, glucocorticoids involved in immune and stress responses, and androgens and estrogens involved in development and homeostasis of reproductive tissues. Understanding CYP17A1 multifunctional biochemistry is thus integral to treating prostate and breast cancer, subfertility, blood pressure, and other diseases. CYP17A1 structures with all four physiologically relevant steroid substrates suggest answers to four fundamental aspects of CYP17A1 function. First, all substrates bind in a similar overall orientation, rising ∼60° with respect to the heme. Second, both hydroxylase substrates pregnenolone and progesterone hydrogen bond to Asn(202) in orientations consistent with production of 17α-hydroxy major metabolites, but functional and structural evidence for an A105L mutation suggests that a minor conformation may yield the minor 16α-hydroxyprogesterone metabolite. Third, substrate specificity of the subsequent 17,20-lyase reaction may be explained by variation in substrate height above the heme. Although 17α-hydroxyprogesterone is only observed farther from the catalytic iron, 17α-hydroxypregnenolone is also observed closer to the heme. In conjunction with spectroscopic evidence, this suggests that only 17α-hydroxypregnenolone approaches and interacts with the proximal oxygen of the catalytic iron-peroxy intermediate, yielding efficient production of dehydroepiandrosterone as the key intermediate in human testosterone and estrogen synthesis. Fourth, differential positioning of 17α-hydroxypregnenolone offers a mechanism whereby allosteric binding of cytochrome b5 might selectively enhance the lyase reaction. In aggregate, these structures provide a structural basis for understanding multiple key reactions at the heart of human steroidogenesis.


    Organizational Affiliation

    From the Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66045 and.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Steroid 17-alpha-hydroxylase/17,20 lyase
A, B, C, D
494Homo sapiensMutation(s): 1 
Gene Names: CYP17A1 (CYP17, S17AH)
EC: 1.14.14.19
Find proteins for P05093 (Homo sapiens)
Go to Gene View: CYP17A1
Go to UniProtKB:  P05093
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, B, C, D
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
3QZ
Query on 3QZ

Download SDF File 
Download CCD File 
A, B, C, D
(9beta)-17-hydroxypregn-4-ene-3,20-dione
C21 H30 O3
DBPWSSGDRRHUNT-CEGNMAFCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.178 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 91.285α = 90.00
b = 151.778β = 90.00
c = 168.045γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
SCALAdata scaling
PHENIXrefinement
XDSdata reduction
Blu-Icedata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-10-22
    Type: Initial release
  • Version 1.1: 2014-12-03
    Type: Database references