1gso

[[Image:1gso.gif|left|200px]]

|PDB= 1gso |SIZE=350|CAPTION= <scene name='initialview01'>1gso</scene>, resolution 1.6&Aring;

|SITE=

|LIGAND=

|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Phosphoribosylamine--glycine_ligase Phosphoribosylamine--glycine ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.4.13 6.3.4.13] </span>

|GENE=

|DOMAIN=

|RELATEDENTRY=

|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1gso FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gso OCA], [http://www.ebi.ac.uk/pdbsum/1gso PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1gso RCSB]</span>

 

'''GLYCINAMIDE RIBONUCLEOTIDE SYNTHETASE (GAR-SYN) FROM E. COLI.'''

 

 

==Overview==

Glycinamide ribonucleotide synthetase (GAR-syn) catalyzes the second step of the de novo purine biosynthetic pathway; the conversion of phosphoribosylamine, glycine, and ATP to glycinamide ribonucleotide (GAR), ADP, and Pi. GAR-syn containing an N-terminal polyhistidine tag was expressed as the SeMet incorporated protein for crystallographic studies. In addition, the protein as isolated contains a Pro294Leu mutation. This protein was crystallized, and the structure solved using multiple-wavelength anomalous diffraction (MAD) phase determination and refined to 1.6 A resolution. GAR-syn adopts an alpha/beta structure that consists of four domains labeled N, A, B, and C. The N, A, and C domains are clustered to form a large central core structure whereas the smaller B domain is extended outward. Two hinge regions, which might readily facilitate interdomain movement, connect the B domain and the main core. A search of structural databases showed that the structure of GAR-syn is similar to D-alanine:D-alanine ligase, biotin carboxylase, and glutathione synthetase, despite low sequence similarity. These four enzymes all utilize similar ATP-dependent catalytic mechanisms even though they catalyze different chemical reactions. Another ATP-binding enzyme with low sequence similarity but unknown function, synapsin Ia, was also found to share high structural similarity with GAR-syn. Interestingly, the GAR-syn N domain shows similarity to the N-terminal region of glycinamide ribonucleotide transformylase and several dinucleotide-dependent dehydrogenases. Models of ADP and GAR binding were generated based on structure and sequence homology. On the basis of these models, the active site lies in a cleft between the large domain and the extended B domain. Most of the residues that facilitate ATP binding belong to the A or B domains. The N and C domains appear to be largely responsible for substrate specificity. The structure of GAR-syn allows modeling studies of possible channeling complexes with PPRP amidotransferase.

 

1GSO is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GSO OCA].

 

==Reference==

X-ray crystal structure of glycinamide ribonucleotide synthetase from Escherichia coli., Wang W, Kappock TJ, Stubbe J, Ealick SE, Biochemistry. 1998 Nov 10;37(45):15647-62. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9843369 9843369]

[[Category: Phosphoribosylamine--glycine ligase]]

[[Category: Single protein]]

[[Category: Ealick, S E.]]

[[Category: Kappock, T J.]]

[[Category: Stubbe, J.]]

[[Category: Wang, W.]]