2AN0: Crystal Structure Of The P332g Mutant Of The Bacillus Subtilis Nos

Cooperativity among ligand binding, subunit association, and protein folding has implications for enzyme regulation as well as protein aggregation events associated with disease. The binding of substrate l-arginine or cofactor tetrahydrobiopterin converts nitric oxide synthases (NOSs) from a "loose dimer", with an exposed active center and higher sensitivity to proteolysis, to a "tight dimer" competent for catalysis. The crystallographic structure of the Bacillus subtilis NOS loose dimer shows an altered association state with severely destabilized subdomains. Ligand binding or heme reduction converts loose dimers to tight dimers in solution and crystals. Mutations at key positions in the dimer interface that distinguish prokaryotic from eukaryotic NOSs affect the propensity to form loose dimers. The loose dimer structure indicates that non-native interactions can mediate subunit association in NOS.
PDB ID: 2AN0Download
MMDB ID: 40651
PDB Deposition Date: 2005/8/10
Updated in MMDB: 2016/12
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Similar Structures:
Biological Unit for 2AN0: dimeric; determined by author and by software (PISA,PQS)
Molecular Components in 2AN0
Label Count Molecule
Proteins (2 molecules)
Nitric Oxide Synthase(Gene symbol: nosA)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB