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PDBsum entry 1aam

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Aminotransferase PDB id
1aam
Jmol
Contents
Protein chain
396 a.a. *
Ligands
SO4
PLP
* Residue conservation analysis
PDB id:
1aam
Name: Aminotransferase
Title: The structural basis for the altered substrate specificity o r292d active site mutant of aspartate aminotransferase from
Structure: Aspartate aminotransferase. Chain: a. Engineered: yes. Mutation: yes
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562
Biol. unit: Dimer (from PQS)
Resolution:
2.80Å     R-factor:   0.203    
Authors: S.C.Almo,D.L.Smith,A.T.Danishefsky,D.Ringe
Key ref: S.C.Almo et al. (1994). The structural basis for the altered substrate specificity of the R292D active site mutant of aspartate aminotransferase from E. coli. Protein Eng, 7, 405-412. PubMed id: 7909946
Date:
13-Jul-93     Release date:   31-Oct-93    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
P00509  (AAT_ECOLI) -  Aspartate aminotransferase
Seq:
Struc:
396 a.a.
396 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class: E.C.2.6.1.1  - Aspartate transaminase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate
L-aspartate
+ 2-oxoglutarate
= oxaloacetate
+ L-glutamate
      Cofactor: Pyridoxal 5'-phosphate
Pyridoxal 5'-phosphate
Bound ligand (Het Group name = PLP) matches with 93.75% similarity
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   2 terms 
  Biological process     biosynthetic process   4 terms 
  Biochemical function     catalytic activity     8 terms  

 

 
    reference    
 
 
Protein Eng 7:405-412 (1994)
PubMed id: 7909946  
 
 
The structural basis for the altered substrate specificity of the R292D active site mutant of aspartate aminotransferase from E. coli.
S.C.Almo, D.L.Smith, A.T.Danishefsky, D.Ringe.
 
  ABSTRACT  
 
Two refined crystal structures of aspartate aminotransferase from E. coli are reported. The wild type enzyme is in the pyridoxal phosphate (PLP) form and its structure has been determined to 2.4 A resolution, refined to an R-factor of 23.2%. The structure of the Arg292Asp mutant has been determined at 2.8 A resolution, refined to an R-factor of 20.3%. The wild type and mutant crystals are isomorphous and the two structures are very similar, with only minor changes in positions of important active site residues. As residue Arg292 is primarily responsible for the substrate charge specificity in the wild type enzyme, the mutant containing a charge reversal at this position might be expected to catalyze transamination of arginine as efficiently as the wild type enzyme effects transamination of aspartate [Cronin, C.N. and Kirsch, J.F. (1988) Biochemistry, 27, 4572-4579]. This mutant does in fact prefer arginine over aspartate as a substrate, however, the rate of catalysis is much slower than that of the wild type enzyme with its physiological substrate, aspartate. A comparison of these two structures indicates that the poorer catalytic efficiency of R292D, when presented with arginine, is not due to a gross conformational difference, but is rather a consequence of both small side chain and main chain reorientations and the pre-existing active site polar environment, which greatly favors the wild type ion pair interaction.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
  21332942 H.J.Wu, Y.Yang, S.Wang, J.Q.Qiao, Y.F.Xia, Y.Wang, W.D.Wang, S.F.Gao, J.Liu, P.Q.Xue, and X.W.Gao (2011).
Cloning, expression and characterization of a new aspartate aminotransferase from Bacillus subtilis B3.
  FEBS J, 278, 1345-1357.  
17300176 S.Lima, R.Khristoforov, C.Momany, and R.S.Phillips (2007).
Crystal structure of Homo sapiens kynureninase.
  Biochemistry, 46, 2735-2744.
PDB code: 2hzp
10491128 J.E.Nielsen, L.Beier, D.Otzen, T.V.Borchert, H.B.Frantzen, K.V.Andersen, and A.Svendsen (1999).
Electrostatics in the active site of an alpha-amylase.
  Eur J Biochem, 264, 816-824.  
  9732276 F.W.Whipple, E.F.Hou, and A.Hochschild (1998).
Amino acid-amino acid contacts at the cooperativity interface of the bacteriophage lambda and P22 repressors.
  Genes Dev, 12, 2791-2802.  
9063881 J.P.Shaw, G.A.Petsko, and D.Ringe (1997).
Determination of the structure of alanine racemase from Bacillus stearothermophilus at 1.9-A resolution.
  Biochemistry, 36, 1329-1342.
PDB code: 1sft
9433130 R.A.Laskowski, E.G.Hutchinson, A.D.Michie, A.C.Wallace, M.L.Jones, and J.M.Thornton (1997).
PDBsum: a Web-based database of summaries and analyses of all PDB structures.
  Trends Biochem Sci, 22, 488-490.  
9265632 Y.Park, J.Luo, P.G.Schultz, and J.F.Kirsch (1997).
Noncoded amino acid replacement probes of the aspartate aminotransferase mechanism.
  Biochemistry, 36, 10517-10525.  
8797848 R.Contestabile, and R.A.John (1996).
The mechanism of high-yielding chiral syntheses catalysed by wild-type and mutant forms of aspartate aminotransferase.
  Eur J Biochem, 240, 150-155.  
  8976563 W.M.Jones, P.W.van Ophem, M.A.Pospischil, D.Ringe, G.Petsko, K.Soda, and J.M.Manning (1996).
The ubiquitous cofactor NADH protects against substrate-induced inhibition of a pyridoxal enzyme.
  Protein Sci, 5, 2545-2551.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.