PDBsum entry 2bht

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protein Protein-protein interface(s) links
Transferase PDB id
Protein chains
294 a.a. *
Waters ×223
* Residue conservation analysis
PDB id:
Name: Transferase
Title: Crystal structure of o-acetylserine sulfhydrylase b
Structure: Cysteine synthase b. Chain: a, b, c, d. Synonym: o-acetylserine sulfhydrylase b, o-acetylserine (thiol)-lyase b, csase b, o-acetylserine sulfhydrylase b. Engineered: yes. Mutation: yes. Other_details: schiff base link between a41 and plp320
Source: Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 469008.
Biol. unit: Dimer (from PDB file)
2.10Å     R-factor:   0.225     R-free:   0.244
Authors: M.T.Claus,G.E.Zocher,T.H.P.Maier,G.E.Schulz
Key ref:
M.T.Claus et al. (2005). Structure of the O-acetylserine sulfhydrylase isoenzyme CysM from Escherichia coli. Biochemistry, 44, 8620-8626. PubMed id: 15952768 DOI: 10.1021/bi050485+
18-Jan-05     Release date:   22-Jun-05    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P16703  (CYSM_ECOLI) -  Cysteine synthase B
303 a.a.
294 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 4 residue positions (black crosses)

 Enzyme reactions 
   Enzyme class: E.C.  - Cysteine synthase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: O-acetyl-L-serine + hydrogen sulfide = L-cysteine + acetate
+ hydrogen sulfide
= L-cysteine
+ acetate
      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!
  Biological process     cellular amino acid biosynthetic process   3 terms 
  Biochemical function     L-cysteine desulfhydrase activity     3 terms  


DOI no: 10.1021/bi050485+ Biochemistry 44:8620-8626 (2005)
PubMed id: 15952768  
Structure of the O-acetylserine sulfhydrylase isoenzyme CysM from Escherichia coli.
M.T.Claus, G.E.Zocher, T.H.Maier, G.E.Schulz.
The enzyme O-acetylserine sulfhydrylase participates in the biosynthesis of l-cysteine in bacteria and plants. The structure of isoenzyme B (CysM) from Escherichia coli was established in a hexagonal crystal form at 2.7 A resolution (wild-type) and in a merohedrally twinned tetragonal crystal form at 2.1 A resolution (surface mutant). Structural superpositions revealed the variations with respect to isoenzyme A (CysK) and explained the different substrate specificities. A geometric model of the reaction catalyzed by CysM is proposed. Both isoenzymes are used for the production of l-amino acid derivatives as building blocks for the synthesis of peptides and peptidomimetic drugs. Since the structure of CysM revealed a remarkable main chain variation at the active center, it constitutes a further starting point for engineering mutants with novel substrate specificities.

Literature references that cite this PDB file's key reference

  PubMed id Reference
20020161 F.Blachier, A.M.Davila, S.Mimoun, P.H.Benetti, C.Atanasiu, M.Andriamihaja, R.Benamouzig, F.Bouillaud, and D.Tomé (2010).
Luminal sulfide and large intestine mucosa: friend or foe?
  Amino Acids, 39, 335-347.  
19640845 M.Goto, T.Yamauchi, N.Kamiya, I.Miyahara, T.Yoshimura, H.Mihara, T.Kurihara, K.Hirotsu, and N.Esaki (2009).
Crystal structure of a homolog of mammalian serine racemase from Schizosaccharomyces pombe.
  J Biol Chem, 284, 25944-25952.
PDB codes: 1wtc 2zr8
19296828 R.A.Williams, G.D.Westrop, and G.H.Coombs (2009).
Two pathways for cysteine biosynthesis in Leishmania major.
  Biochem J, 420, 451-462.  
18799456 D.Agren, R.Schnell, W.Oehlmann, M.Singh, and G.Schneider (2008).
Cysteine Synthase (CysM) of Mycobacterium tuberculosis Is an O-Phosphoserine Sulfhydrylase: EVIDENCE FOR AN ALTERNATIVE CYSTEINE BIOSYNTHESIS PATHWAY IN MYCOBACTERIA.
  J Biol Chem, 283, 31567-31574.
PDB code: 3dki
18187656 D.Grueninger, N.Treiber, M.O.Ziegler, J.W.Koetter, M.S.Schulze, and G.E.Schulz (2008).
Designed protein-protein association.
  Science, 319, 206-209.
PDB codes: 2uyu 2uyv 2v7g 2v9e 2v9f 2v9g 2v9i 2v9l 2v9m 2v9n 2v9o 2v9u
18350570 K.Chinthalapudi, M.Kumar, S.Kumar, S.Jain, N.Alam, and S.Gourinath (2008).
Crystal structure of native O-acetyl-serine sulfhydrylase from Entamoeba histolytica and its complex with cysteine: structural evidence for cysteine binding and lack of interactions with serine acetyl transferase.
  Proteins, 72, 1222-1232.
PDB codes: 2pqm 3bm5
  17554175 C.Krishna, R.Jain, T.Kashav, D.Wadhwa, N.Alam, and S.Gourinath (2007).
Crystallization and preliminary crystallographic analysis of cysteine synthase from Entamoeba histolytica.
  Acta Crystallogr Sect F Struct Biol Cryst Commun, 63, 512-515.  
17894825 G.Zocher, U.Wiesand, and G.E.Schulz (2007).
High resolution structure and catalysis of O-acetylserine sulfhydrylase isozyme B from Escherichia coli.
  FEBS J, 274, 5382-5389.
PDB code: 2v03
17567578 R.Schnell, W.Oehlmann, M.Singh, and G.Schneider (2007).
Structural insights into catalysis and inhibition of O-acetylserine sulfhydrylase from Mycobacterium tuberculosis. Crystal structures of the enzyme alpha-aminoacrylate intermediate and an enzyme-inhibitor complex.
  J Biol Chem, 282, 23473-23481.
PDB codes: 2q3b 2q3c 2q3d
16735516 G.D.Westrop, G.Goodall, J.C.Mottram, and G.H.Coombs (2006).
Cysteine biosynthesis in Trichomonas vaginalis involves cysteine synthase utilizing O-phosphoserine.
  J Biol Chem, 281, 25062-25075.  
16166087 E.R.Bonner, R.E.Cahoon, S.M.Knapke, and J.M.Jez (2005).
Molecular basis of cysteine biosynthesis in plants: structural and functional analysis of O-acetylserine sulfhydrylase from Arabidopsis thaliana.
  J Biol Chem, 280, 38803-38813.
PDB codes: 1z7w 1z7y
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.