Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	The subnanometer resolution structure of the glutamate synthase 1.2-MDa hexamer by cryoelectron microscopy and its oligomerization behavior in solution: functional implications.
Journal, issue, pages	J Biol Chem, Vol. 283, Issue 13, Page 8237-8249, Year 2008
Publish date	Mar 28, 2008
Authors	Magali Cottevieille / Eric Larquet / Slavica Jonic / Maxim V Petoukhov / Gianluca Caprini / Stefano Paravisi / Dmitri I Svergun / Maria A Vanoni / Nicolas Boisset /
PubMed Abstract	The three-dimensional structure of the hexameric (alphabeta)(6) 1.2-MDa complex formed by glutamate synthase has been determined at subnanometric resolution by combining cryoelectron microscopy, ...The three-dimensional structure of the hexameric (alphabeta)(6) 1.2-MDa complex formed by glutamate synthase has been determined at subnanometric resolution by combining cryoelectron microscopy, small angle x-ray scattering, and molecular modeling, providing for the first time a molecular model of this complex iron-sulfur flavoprotein. In the hexameric species, interprotomeric alpha-alpha and alpha-beta contacts are mediated by the C-terminal domain of the alpha subunit, which is based on a beta helical fold so far unique to glutamate synthases. The alphabeta protomer extracted from the hexameric model is fully consistent with it being the minimal catalytically active form of the enzyme. The structure clarifies the electron transfer pathway from the FAD cofactor on the beta subunit, to the FMN on the alpha subunit, through the low potential [4Fe-4S](1+/2+) centers on the beta subunit and the [3Fe-4S](0/1+) cluster on the alpha subunit. The (alphabeta)(6) hexamer exhibits a concentration-dependent equilibrium with alphabeta monomers and (alphabeta)(2) dimers, in solution, the hexamer being destabilized by high ionic strength and, to a lower extent, by the reaction product NADP(+). Hexamerization seems to decrease the catalytic efficiency of the alphabeta protomer only 3-fold by increasing the K(m) values measured for l-Gln and 2-OG. However, it cannot be ruled out that the (alphabeta)(6) hexamer acts as a scaffold for the assembly of multienzymatic complexes of nitrogen metabolism or that it provides a means to regulate the activity of the enzyme through an as yet unknown ligand.
External links	J Biol Chem / PubMed:18199747
Methods	EM (single particle)
Resolution	9.5 Å
Structure data	1440 2vdc EMDB-1440: The subnanometer resolution structure of the glutamate synthase 1.2-MDa hexamer by cryoelectron microscopy and its oligomerization behavior in solution: functional implications. PDB-2vdc: THE 9.5 A RESOLUTION STRUCTURE OF GLUTAMATE SYNTHASE FROM CRYO-ELECTRON MICROSCOPY AND ITS OLIGOMERIZATION BEHAVIOR IN SOLUTION: FUNCTIONAL IMPLICATIONS. Method: EM (single particle) / Resolution: 9.5 Å
Chemicals	ChemComp-OMT: S-DIOXYMETHIONINE ChemComp-FMN: FLAVIN MONONUCLEOTIDE / Flavin mononucleotide ChemComp-AKG: 2-OXOGLUTARIC ACID / Α-Ketoglutaric acid ChemComp-F3S: FE3-S4 CLUSTER / Iron–sulfur cluster ChemComp-SF4: IRON/SULFUR CLUSTER / Iron–sulfur cluster ChemComp-FAD: FLAVIN-ADENINE DINUCLEOTIDE / FAD*YM / Flavin adenine dinucleotide
Source	azospirillum brasilense (bacteria)
Keywords	OXIDOREDUCTASE / AMIDOTRANSFERASE / AMMONIA ASSIMILATION / NADP / IRON / ZYMOGEN / NADPH-DEPENDENT GLUTAMATE SYNTHASE / IRON SULPHUR FLAVOPROTEIN / GLUTAMINE AMIDOTRANSFERASE / GLUTAMATE BIOSYNTHESIS / AMINO-ACID BIOSYNTHESIS