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PDBsum entry 1mez

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protein ligands metals links
Ligase PDB id
1mez
Jmol
Contents
Protein chain
430 a.a. *
Ligands
SO4
GDP
2SA
Metals
_MG
Waters ×121
* Residue conservation analysis
PDB id:
1mez
Name: Ligase
Title: Structure of the recombinant mouse-muscle adenylosuccinate s complexed with samp, gdp, so4(2-), and mg(2+)
Structure: Adenylosuccinate synthetase. Chain: a. Synonym: adss, ampsase. Engineered: yes
Source: Mus musculus. House mouse. Organism_taxid: 10090. Gene: adss1. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.
Biol. unit: Dimer (from PDB file)
Resolution:
2.40Å     R-factor:   0.221     R-free:   0.275
Authors: C.V.Iancu,T.Borza,H.J.Fromm,R.B.Honzatko
Key ref:
C.V.Iancu et al. (2002). Feedback inhibition and product complexes of recombinant mouse muscle adenylosuccinate synthetase. J Biol Chem, 277, 40536-40543. PubMed id: 12186864 DOI: 10.1074/jbc.M204952200
Date:
09-Aug-02     Release date:   30-Oct-02    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
P28650  (PURA1_MOUSE) -  Adenylosuccinate synthetase isozyme 1
Seq:
Struc:
457 a.a.
430 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.6.3.4.4  - Adenylosuccinate synthase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]

      Pathway:
AMP and GMP Biosynthesis
      Reaction: GTP + IMP + L-aspartate = GDP + phosphate + N6-(1,2-dicarboxyethyl)- AMP
GTP
+ IMP
+ L-aspartate
=
GDP
Bound ligand (Het Group name = GDP)
corresponds exactly
+ phosphate
+
N(6)-(1,2-dicarboxyethyl)- AMP
Bound ligand (Het Group name = 2SA)
corresponds exactly
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     membrane   2 terms 
  Biological process     cellular response to drug   13 terms 
  Biochemical function     nucleotide binding     10 terms  

 

 
    reference    
 
 
DOI no: 10.1074/jbc.M204952200 J Biol Chem 277:40536-40543 (2002)
PubMed id: 12186864  
 
 
Feedback inhibition and product complexes of recombinant mouse muscle adenylosuccinate synthetase.
C.V.Iancu, T.Borza, H.J.Fromm, R.B.Honzatko.
 
  ABSTRACT  
 
Adenylosuccinate synthetase governs the committed step of AMP biosynthesis, the generation of 6-phosphoryl-IMP from GTP and IMP followed by the formation of adenylosuccinate from 6-phosphoryl-IMP and l-aspartate. The enzyme is subject to feedback inhibition by AMP and adenylosuccinate, but crystallographic complexes of the mouse muscle synthetase presented here infer mechanisms of inhibition that involve potentially synergistic ligand combinations. AMP alone adopts the productive binding mode of IMP and yet stabilizes the active site in a conformation that favors the binding of Mg(2+)-IMP to the GTP pocket. On the other hand, AMP, in the presence of GDP, orthophosphate, and Mg(2+), adopts the binding mode of adenylosuccinate. Depending on circumstances then, AMP behaves as an analogue of IMP or as an analogue of adenylosuccinate. The complex of adenylosuccinate.GDP.Mg(2+).sulfate, the first structure of an adenylosuccinate-bound synthetase, reveals significant geometric distortions and tight nonbonded contacts relevant to the proposed catalytic mechanism. Adenylosuccinate forms from 6-phosphoryl-IMP and l-aspartate by the movement of the purine ring into the alpha-amino group of l-aspartate.
 
  Selected figure(s)  
 
Figure 2.
Fig. 2. Stereoview of AMP bound to the active site. Electron density is from an omit map (coefficients of 2F[obs] F[calc], [calc] phases) contoured at 3 using a cut-off radius of 1 Å. Dashed lines represent donor-acceptor interactions.
Figure 4.
Fig. 4. Stereoview of SAMP-product complex. Electron density covering SAMP is from an omit map (coefficients of 2 F[obs] F[calc], [calc] phases) contoured at 3 using a cut-off radius of 1 Å. Dashed lines represent donor-acceptor interactions and coordinate bonds to the Mg2+.
 
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2002, 277, 40536-40543) copyright 2002.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
16216072 J.A.Endrizzi, H.Kim, P.M.Anderson, and E.P.Baldwin (2005).
Mechanisms of product feedback regulation and drug resistance in cytidine triphosphate synthetases from the structure of a CTP-inhibited complex.
  Biochemistry, 44, 13491-13499.
PDB code: 2ad5
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