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PDBsum entry 1szk

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protein ligands Protein-protein interface(s) links
Transferase PDB id
1szk
Jmol
Contents
Protein chains
425 a.a. *
Ligands
SO4 ×15
EDO ×13
PMP ×4
Waters ×673
* Residue conservation analysis
PDB id:
1szk
Name: Transferase
Title: The structure of gamma-aminobutyrate aminotransferase mutant: e211s
Structure: 4-aminobutyrate aminotransferase. Chain: a, b, c, d. Synonym: gamma-amino-n-butyrate transaminase, gaba transaminase, glutamate:succinic semialdehyde transaminase, gaba aminotransferase, gaba-at. Engineered: yes. Mutation: yes
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693.
Biol. unit: Tetramer (from PQS)
Resolution:
2.52Å     R-factor:   0.187     R-free:   0.240
Authors: W.Liu,P.E.Peterson,J.A.Langston,X.Jin,A.J.Fisher,M.D.Toney
Key ref:
W.Liu et al. (2005). Kinetic and crystallographic analysis of active site mutants of Escherichia coli gamma-aminobutyrate aminotransferase. Biochemistry, 44, 2982-2992. PubMed id: 15723541 DOI: 10.1021/bi048657a
Date:
05-Apr-04     Release date:   01-Mar-05    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chains
Pfam   ArchSchema ?
P22256  (GABT_ECOLI) -  4-aminobutyrate aminotransferase GabT
Seq:
Struc:
426 a.a.
425 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 Enzyme reactions 
   Enzyme class 1: E.C.2.6.1.19  - 4-aminobutyrate--2-oxoglutarate transaminase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: 4-aminobutanoate + 2-oxoglutarate = succinate semialdehyde + L-glutamate
4-aminobutanoate
+
2-oxoglutarate
Bound ligand (Het Group name = EDO)
matches with 40.00% similarity
= succinate semialdehyde
+ L-glutamate
      Cofactor: Pyridoxal 5'-phosphate
Pyridoxal 5'-phosphate
   Enzyme class 2: E.C.2.6.1.22  - (S)-3-amino-2-methylpropionate transaminase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]

      Pathway:
      Reaction: (S)-3-amino-2-methylpropanoate + 2-oxoglutarate = 2-methyl-3- oxopropanoate + L-glutamate
(S)-3-amino-2-methylpropanoate
+
2-oxoglutarate
Bound ligand (Het Group name = EDO)
matches with 40.00% similarity
= 2-methyl-3- oxopropanoate
+ L-glutamate
Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     gamma-aminobutyric acid metabolic process   2 terms 
  Biochemical function     catalytic activity     6 terms  

 

 
    reference    
 
 
DOI no: 10.1021/bi048657a Biochemistry 44:2982-2992 (2005)
PubMed id: 15723541  
 
 
Kinetic and crystallographic analysis of active site mutants of Escherichia coli gamma-aminobutyrate aminotransferase.
W.Liu, P.E.Peterson, J.A.Langston, X.Jin, X.Zhou, A.J.Fisher, M.D.Toney.
 
  ABSTRACT  
 
The E. coli isozyme of gamma-aminobutyrate aminotransferase (GABA-AT) is a tetrameric pyridoxal phosphate-dependent enzyme that catalyzes transamination between primary amines and alpha-keto acids. The roles of the active site residues V241, E211, and I50 in the GABA-AT mechanism have been probed by site-directed mutagenesis. The beta-branched side chain of V241 facilitates formation of external aldimine intermediates with primary amine substrates, while E211 provides charge compensation of R398 selectively in the primary amine half-reaction and I50 forms a hydrophobic lid at the top of the substrate binding site. The structures of the I50Q, V241A, and E211S mutants were solved by X-ray crystallography to resolutions of 2.1, 2.5, and 2.52 A, respectively. The structure of GABA-AT is similar in overall fold and active site structure to that of dialkylglycine decarboxylase, which catalyzes both transamination and decarboxylation half-reactions in its normal catalytic cycle. Therefore, an attempt was made to convert GABA-AT into a decarboxylation-dependent aminotransferase similar to dialkylglycine decarboxylase by systematic mutation of E. coli GABA-AT active site residues. Two of the twelve mutants presented, E211S/I50G/C77K and E211S/I50H/V80D, have approximately 10-fold higher decarboxylation activities than the wild-type enzyme, and the E211S/I50H/V80D has formally changed the reaction specificity to that of a decarboxylase.
 

Literature references that cite this PDB file's key reference

  PubMed id Reference
20639325 S.Kurihara, K.Kato, K.Asada, H.Kumagai, and H.Suzuki (2010).
A putrescine-inducible pathway comprising PuuE-YneI in which gamma-aminobutyrate is degraded into succinate in Escherichia coli K-12.
  J Bacteriol, 192, 4582-4591.  
18487339 C.Gross, R.Felsheim, and L.P.Wackett (2008).
Genes and enzymes of azetidine-2-carboxylate metabolism: detoxification and assimilation of an antibiotic.
  J Bacteriol, 190, 4859-4864.  
17355287 G.Andersen, B.Andersen, D.Dobritzsch, K.D.Schnackerz, and J.Piskur (2007).
A gene duplication led to specialized gamma-aminobutyrate and beta-alanine aminotransferase in yeast.
  FEBS J, 274, 1804-1817.  
17185223 B.Julien, Z.Q.Tian, R.Reid, and C.D.Reeves (2006).
Analysis of the ambruticin and jerangolid gene clusters of Sorangium cellulosum reveals unusual mechanisms of polyketide biosynthesis.
  Chem Biol, 13, 1277-1286.  
16096275 M.Markova, C.Peneff, M.J.Hewlins, T.Schirmer, and R.A.John (2005).
Determinants of substrate specificity in omega-aminotransferases.
  J Biol Chem, 280, 36409-36416.
PDB codes: 2byj 2byl
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