Biological Assembly 1  

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Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

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

Macromolecule Content

• Total Structure Weight: 100408.96 
• Atom Count: 6878 
• Residue Count: 842 
• Unique protein chains: 1

1P6K

Rat neuronal NOS D597N mutant heme domain with L-N(omega)-nitroarginine-2,4-L-diaminobutyric amide bound

• DOI: 10.2210/pdb1P6K/pdb

• Classification: OXIDOREDUCTASE
• Organism(s): Rattus norvegicus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): 1 


• Deposited: 2003-04-29 Released: 2004-01-13 
• Deposition Author(s): Flinspach, M.L., Li, H., Jamal, J., Yang, W., Huang, H., Hah, J.-M., Gomez-Vidal, J.A., Litzinger, E.A., Silverman, R.B., Poulos, T.L.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.78 Å
• R-Value Free: 0.250 
• R-Value Work: 0.225 

Literature

Structural basis for dipeptide amide isoform-selective inhibition of neuronal nitric oxide synthase.

Flinspach, M.L., Li, H., Jamal, J., Yang, W., Huang, H., Hah, J.M., Gomez-Vidal, J.A., Litzinger, E.A., Silverman, R.B., Poulos, T.L.

(2004) Nat.Struct.Mol.Biol. 11: 54-59

• PubMed: 14718923 
• DOI: 10.1038/nsmb704
• Primary Citation of Related Structures:  
  1P6J, 1Q2O, 1P6N, 1P6M, 1P6L, 1P6I, 1P6H
• Also Cited By: 2HX4, 2HX3, 2HX2, 1ZZU, 1ZZT, 1ZZS, 1ZZR, 1ZZQ


• PubMed Abstract: 
  

Three nitric oxide synthase (NOS) isoforms, eNOS, nNOS and iNOS, generate nitric oxide (NO) crucial to the cardiovascular, nervous and host defense systems, respectively. Development of isoform-selective NOS inhibitors is of considerable therapeutic importance. Crystal structures of nNOS-selective dipeptide inhibitors in complex with both nNOS and eNOS were solved and the inhibitors were found to adopt a curled conformation in nNOS but an extended conformation in eNOS. We hypothesized that a single-residue difference in the active site, Asp597 (nNOS) versus Asn368 (eNOS), is responsible for the favored binding in nNOS. In the D597N nNOS mutant crystal structure, a bound inhibitor switches to the extended conformation and its inhibition of nNOS decreases >200-fold. Therefore, a single-residue difference is responsible for more than two orders of magnitude selectivity in inhibition of nNOS over eNOS by L-N(omega)-nitroarginine-containing dipeptide inhibitors.

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Related Citations: 

• The novel binding mode of N-alkyl-N'-hydroxyguanidine to neuronal nitric oxide synthase provides mechanistic insights into NO biosynthesis
  Li, H.,Shimizu, H.,Flinspach, M.,Jamal, J.,Yang, W.,Xian, M.,Cai, T.,Wen, E.Z.,Jia, Q.,Wang, P.G.,Poulos, T.L.
  (2002) Biochemistry 41: 13868
• CRYSTAL STRUCTURE OF CONSTITUTIVE ENDOTHELIAL NITRIC OXIDE SYNTHASE: A PARADIGM FOR PTERIN FUNCTION INVOLVING A NOVEL METAL CENTER
  Raman, C.S.,Li, H.,Martasek, P.,Kral, V.,Masters, B.S.S.,Poulos, T.L.
  (1998) Cell 95: 939




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Organizational Affiliation: 

Department of Molecular Biology and Biochemistry and the Program in Macromolecular Structure, University of California, Irvine, California 92697-3900, USA.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Nitric-oxide synthase, brain	A, B	421	Rattus norvegicus	Mutation(s): 1  Gene Names: Nos1 (Bnos) EC: 1.14.13.39
Find proteins for P29476 (Rattus norvegicus) Go to UniProtKB:  P29476

Small Molecules

Ligands 6 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
DP1	A, B	L-N(OMEGA)-NITROARGININE-2,4-L-DIAMINOBUTYRIC AMIDE C10 H22 N8 O4 KUZKVXUOMSVPOA-BQBZGAKWSA-N
ZN	A	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N
ACT	A, B	ACETATE ION C2 H3 O2 QTBSBXVTEAMEQO-UHFFFAOYSA-M
MTL	A, B	D-MANNITOL C6 H14 O6 FBPFZTCFMRRESA-KVTDHHQDSA-N
HEM	A, B	PROTOPORPHYRIN IX CONTAINING FE HEME C34 H32 Fe N4 O4 KABFMIBPWCXCRK-RGGAHWMASA-L
H4B	A, B	5,6,7,8-TETRAHYDROBIOPTERIN C9 H15 N5 O3 FNKQXYHWGSIFBK-RPDRRWSUSA-N

External Ligand Annotations
ID	Binding Affinity (Sequence Identity %)
DP1	Ki: 130 nM (99) BINDINGDB
DP1	Ki: 67000 nM BINDINGMOAD

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.78 Å
• R-Value Free: 0.250 
• R-Value Work: 0.225 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length (Å)	Angle (°)
a = 51.770	α = 90.00
b = 109.740	β = 90.00
c = 164.390	γ = 90.00

Software Package:

Software Name	Purpose
CNS	phasing
SCALEPACK	data scaling
CNS	refinement
HKL-2000	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-04-29 
• Released Date: 2004-01-13 
• Deposition Author(s): Flinspach, M.L., Li, H., Jamal, J., Yang, W., Huang, H., Hah, J.-M., Gomez-Vidal, J.A., Litzinger, E.A., Silverman, R.B., Poulos, T.L.

Revision History 

• Version 1.0: 2004-01-13
  Type: Initial release
• Version 1.1: 2008-04-29
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Version format compliance