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Contents 1 Glutamine Synthetase 1.1 Structure 1.2 Classes 1.3 References

Glutamine Synthetase

Structure

An unrefined structure of glutamine synthetase is made of two layers, each containing 6 subunits, for a total of 12 subunits. ^[1] Each subunit contains an which is defined by a cylindrical shape formed by six antiparalel β starnds contributed by one subunit and two more strands by the neighbouring subunit. ^[1] In each cylindrical active site there are two Mn2+ ions: Mn 2+ 469 and 470. Both are attached to three protein chains and two water molecules, one of the water molecules are shared by both Mn2+. The protein ligands. Attached to Mn 2+ 469 is: Glu-131, GLu-212 and Glu-220, and the protein ligands attached to Mn 2+ are: Glu-129, His-269 and Glu-357.^[1]

Unique to glutamine synthetase, unlike other enzymes, is it's "passive site". This refers to the central loop which is formed by a segment of the backbone that extends into the central aqueous cavity. ^[1]Unlike other sites in glutamine synthetase under the same conditions, this site is suceptible to proteolysis by four secreated proteases from the V8 protease of Staphylococcus aureus.^[1]

spinqualitylabelsall models PDB ID 2gls Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
2gls, resolution 3.50Å ()
Ligands:
Activity:	Glutamate--ammonia ligase, with EC number 6.3.1.2
Structural annotation: Resources: CATH : 2Glsa02, 2Glsa01, 2Glsb02, 2Glsb01, 2Glsc01, 2Glsc02, 2Glsd02, 2Glsd01, 2Glse02, 2Glse01, 2Glsf02, 2Glsf01, 2Glsg01, 2Glsg02, 2Glsh02, 2Glsh01, 2Glsi02, 2Glsi01, 2Glsj01, 2Glsj02, 2Glsk01, 2Glsk02, 2Glsl02, 2Glsl01 InterPro : Ipr014746, Ipr008146, Ipr001637, Ipr008147, Ipr004809 Pfam : PF00120, PF03951 SCOP : d2glsa2, d2glsa1, d2glsb2, d2glsb1, d2glsc1, d2glsc2, d2glsd2, d2glsd1, d2glse2, d2glse1, d2glsf1, d2glsf2, d2glsg2, d2glsg1, d2glsh2, d2glsh1, d2glsi2, d2glsi1, d2glsj2, d2glsj1, d2glsk1, d2glsk2, d2glsl2, d2glsl1 UniProt : P0A1P6
Functional annotation: Cellular component: cytoplasm Biological process: nitrogen compound metabolic process glutamine biosynthetic process nitrogen fixation Molecular function: ligase activity nucleotide binding glutamate-ammonia ligase activity catalytic activity
Evolutionary conservation: Toggle Conservation Colors: Rows = identical sequences: Further Information: Caveats, Explanation, Complete Results at ConSurfDB
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

Classes

Glutamine synthetase has been described as having three destinctive types.^[2]

• Class I (GSI): Genes for this class have only been found in bacteria (eubacteria) and archaea (arhaebacteria. The paper by Kumada et. al goes into detail on these two.^[2]
• Class II (GSII): Genes for this class have only been found in eukaryotes and a few soil-dwelling bacteria.The paper by Kumada again, gets into further detail about these bacteria.^[2]

References

1. ↑ ^{1.0 1.1 1.2 1.3 1.4} Yamashita MM, Almassy RJ, Janson CA, Cascio D, Eisenberg D. Refined atomic model of glutamine synthetase at 3.5 A resolution. J Biol Chem. 1989 Oct 25;264(30):17681-90. PMID:2572586
2. ↑ ^{2.0 2.1 2.2} Brown JR, Masuchi Y, Robb FT, Doolittle WF. Evolutionary relationships of bacterial and archaeal glutamine synthetase genes. J Mol Evol. 1994 Jun;38(6):566-76. PMID:7916055

Rhiannon Khela

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