PDBsum entry 1szk

Go to PDB code: 
protein ligands Protein-protein interface(s) links
Transferase PDB id
Protein chains
425 a.a. *
SO4 ×15
EDO ×13
PMP ×4
Waters ×673
* Residue conservation analysis
PDB id:
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)
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
05-Apr-04     Release date:   01-Mar-05    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P22256  (GABT_ECOLI) -  4-aminobutyrate aminotransferase GabT
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.  - 4-aminobutyrate--2-oxoglutarate transaminase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: 4-aminobutanoate + 2-oxoglutarate = succinate semialdehyde + L-glutamate
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.  - (S)-3-amino-2-methylpropionate transaminase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]

      Reaction: (S)-3-amino-2-methylpropanoate + 2-oxoglutarate = 2-methyl-3- oxopropanoate + L-glutamate
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  


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.
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
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 codes are shown on the right.