1cib
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1cib.jpg|left|200px]] | [[Image:1cib.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1cib", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_1cib| PDB=1cib | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''STRUCTURE OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH GDP, IMP, HADACIDIN, AND NO3''' | '''STRUCTURE OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH GDP, IMP, HADACIDIN, AND NO3''' | ||
| Line 30: | Line 27: | ||
[[Category: Honzatko, R B.]] | [[Category: Honzatko, R B.]] | ||
[[Category: Hou, Z.]] | [[Category: Hou, Z.]] | ||
| - | [[Category: | + | [[Category: Gdp]] |
| - | [[Category: | + | [[Category: Gtp-hydrolysing enzyme]] |
| - | [[Category: | + | [[Category: Ligase]] |
| - | [[Category: | + | [[Category: Purine 2 nucleotide biosynthesis]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 12:45:44 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 09:45, 2 May 2008
STRUCTURE OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH GDP, IMP, HADACIDIN, AND NO3
Overview
Guanosine 5'-diphosphate 3'-diphosphate (ppGpp), a pleiotropic effector of the stringent response, potently inhibits adenylosuccinate synthetase from Escherichia coli as an allosteric effector and/or as a competitive inhibitor with respect to GTP. Crystals of the synthetase grown in the presence of IMP, hadacidin, NO3-, and Mg2+, then soaked with ppGpp, reveal electron density at the GTP pocket which is consistent with guanosine 5'-diphosphate 2':3'-cyclic monophosphate. Unlike ligand complexes of the synthetase involving IMP and GDP, the coordination of Mg2+ in this complex is octahedral with the side chain of Asp13 in the inner sphere of the cation. The cyclic phosphoryl group interacts directly with the side chain of Lys49 and indirectly through bridging water molecules with the side chains of Asn295 and Arg305. The synthetase either directly facilitates the formation of the cyclic nucleotide or scavenges trace amounts of the cyclic nucleotide from solution. Regardless of its mode of generation, the cyclic nucleotide binds far more tightly to the active site than does ppGpp. Conceivably, synthetase activity in vivo during the stringent response may be sensitive to the relative concentrations of several effectors, which together exercise precise control over the de novo synthesis of AMP.
About this Structure
1CIB is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Effectors of the stringent response target the active site of Escherichia coli adenylosuccinate synthetase., Hou Z, Cashel M, Fromm HJ, Honzatko RB, J Biol Chem. 1999 Jun 18;274(25):17505-10. PMID:10364182 Page seeded by OCA on Fri May 2 12:45:44 2008
