4CVG

Structure of bovine endothelial nitric oxide synthase heme domain (H4B-free) supplemented with 50uM Zn acetate and with poor binding of 6-acetyl-2-amino-7,7-dimethyl-7,8-dihydropteridin-4(3H)-one.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.31 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.155 
  • R-Value Observed: 0.158 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Communication between the Zinc and Tetrahydrobiopterin Binding Sites in Nitric Oxide Synthase.

Chreifi, G.Li, H.Mcinnes, C.R.Gibson, C.L.Suckling, C.J.Poulos, T.L.

(2014) Biochemistry 53: 4216

  • DOI: 10.1021/bi5003986
  • Primary Citation of Related Structures:  
    4CUN, 4CUL, 4CUM, 4CVG

  • PubMed Abstract: 
  • The nitric oxide synthase (NOS) dimer is stabilized by a Zn(2+) ion coordinated to four symmetry-related Cys residues exactly along the dimer 2-fold axis. Each of the two essential tetrahydrobiopterin (H4B) molecules in the dimer interacts directly w ...

    The nitric oxide synthase (NOS) dimer is stabilized by a Zn(2+) ion coordinated to four symmetry-related Cys residues exactly along the dimer 2-fold axis. Each of the two essential tetrahydrobiopterin (H4B) molecules in the dimer interacts directly with the heme, and each H4B molecule is ~15 Å from the Zn(2+). We have determined the crystal structures of the bovine endothelial NOS dimer oxygenase domain bound to three different pterin analogues, which reveal an intimate structural communication between the H4B and Zn(2+) sites. The binding of one of these compounds, 6-acetyl-2-amino-7,7-dimethyl-7,8-dihydro-4(3H)-pteridinone (1), to the pterin site and Zn(2+) binding are mutually exclusive. Compound 1 both directly and indirectly disrupts hydrogen bonding between key residues in the Zn(2+) binding motif, resulting in destabilization of the dimer and a complete disruption of the Zn(2+) site. Addition of excess Zn(2+) stabilizes the Zn(2+) site at the expense of weakened binding of 1. The unique structural features of 1 that disrupt the dimer interface are extra methyl groups that extend into the dimer interface and force a slight opening of the dimer, thus resulting in disruption of the Zn(2+) site. These results illustrate a very delicate balance of forces and structure at the dimer interface that must be maintained to properly form the Zn(2+), pterin, and substrate binding sites.


    Organizational Affiliation

    Departments of †Molecular Biology and Biochemistry, ‡Chemistry, and §Pharmaceutical Sciences, University of California , Irvine, California 92697-3900, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
NITRIC OXIDE SYNTHASE, ENDOTHELIALAB443Bos taurusMutation(s): 0 
Gene Names: NOS3
EC: 1.14.13.39
Find proteins for P29473 (Bos taurus)
Explore P29473 
Go to UniProtKB:  P29473
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download CCD File 
A, B
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
ARG
Query on ARG

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A, B
ARGININE
C6 H15 N4 O2
ODKSFYDXXFIFQN-BYPYZUCNSA-O
 Ligand Interaction
GOL
Query on GOL

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B
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

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A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CAS
Query on CAS
A,BL-PEPTIDE LINKINGC5 H12 As N O2 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.31 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.155 
  • R-Value Observed: 0.158 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.414α = 90
b = 105.957β = 90
c = 156.53γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
REFMACphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-05-28
    Type: Initial release
  • Version 1.1: 2014-07-16
    Changes: Database references