PDBsum entry 1xcf

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protein Protein-protein interface(s) links
Lyase PDB id
Protein chains
238 a.a. *
Waters ×231
* Residue conservation analysis
PDB id:
Name: Lyase
Title: Crystal structure of p28l/y173f tryptophan synthase alpha- subunits from escherichia coli
Structure: Tryptophan synthase alpha chain. Chain: a, b. Synonym: tryptophan synthase a-subunits. Engineered: yes. Mutation: yes
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Monomer (from PDB file)
1.80Å     R-factor:   0.261     R-free:   0.289
Authors: S.B.Jang
Key ref: M.S.Jeong et al. (2004). Structures of wild-type and P28L/Y173F tryptophan synthase alpha-subunits from Escherichia coli. Biochem Biophys Res Commun, 323, 1257-1264. PubMed id: 15451433 DOI: 10.1016/j.bbrc.2004.08.222
01-Sep-04     Release date:   02-Nov-04    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P0A877  (TRPA_ECOLI) -  Tryptophan synthase alpha chain
268 a.a.
238 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 5 residue positions (black crosses)

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

Tryptophan Biosynthesis
      Reaction: L-serine + 1-C-(indol-3-yl)glycerol 3-phosphate = L-tryptophan + D-glyceraldehyde 3-phosphate + H2O
+ 1-C-(indol-3-yl)glycerol 3-phosphate
= L-tryptophan
+ D-glyceraldehyde 3-phosphate
+ H(2)O
      Cofactor: Pyridoxal 5'-phosphate
Pyridoxal 5'-phosphate
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   1 term 
  Biological process     metabolic process   5 terms 
  Biochemical function     catalytic activity     3 terms  


DOI no: 10.1016/j.bbrc.2004.08.222 Biochem Biophys Res Commun 323:1257-1264 (2004)
PubMed id: 15451433  
Structures of wild-type and P28L/Y173F tryptophan synthase alpha-subunits from Escherichia coli.
M.S.Jeong, J.K.Jeong, W.K.Lim, S.B.Jang.
The alpha-subunit of tryptophan synthase (alphaTS) catalyzes the cleavage of indole-3-glycerol phosphate to glyceraldehyde-3-phosphate and indole, which is used to yield the amino acid tryptophan in tryptophan biosynthesis. Here, we report the first crystal structures of wild-type and double-mutant P28L/Y173F alpha-subunit of tryptophan synthase from Escherichia coli at 2.8 and 1.8A resolution, respectively. The structure of wild-type alphaTS from E. coli was similar to that of the alpha(2)beta(2) complex structure from Salmonella typhimurium. As compared with both structures, the conformational changes are mostly in the interface of alpha- and beta-subunits, and the substrate binding region. Two sulfate ions and two glycerol molecules per asymmetric unit bind with the residues in the active sites of the wild-type structure. Contrarily, double-mutant P28L/Y173F structure is highly closed at the window for the substrate binding by the conformational changes. The P28L substitution induces the exposure of hydrophobic amino acids and decreases the secondary structure that causes the aggregation. The Y173F suppresses to transfer a signal from the alpha-subunit core to the alpha-subunit surface involved in interactions with the beta-subunit and increases structural stability.