PDBsum entry 1saz

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protein ligands metals links
Transferase PDB id
Protein chain
375 a.a. *
FMT ×4
Waters ×63
* Residue conservation analysis
PDB id:
Name: Transferase
Title: Membership in the askha superfamily: enzymological properties and crystal structure of butyrate kinase 2 from thermotoga maritima
Structure: Probable butyrate kinase 2. Chain: a. Synonym: bk 2, branched-chain carboxylic acid kinase 2. Engineered: yes
Source: Thermotoga maritima. Organism_taxid: 2336. Gene: buk2, tm1756. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Dimer (from PDB file)
2.50Å     R-factor:   0.217     R-free:   0.267
Authors: J.Diao,D.R.Cooper,D.A.Sanders,M.S.Hasson
Key ref: J.Diao and M.S.Hasson (2009). Crystal structure of butyrate kinase 2 from Thermotoga maritima, a member of the ASKHA superfamily of phosphotransferases. J Bacteriol, 191, 2521-2529. PubMed id: 19201797
09-Feb-04     Release date:   29-Mar-05    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
Q9X278  (BUK2_THEMA) -  Probable butyrate kinase 2
375 a.a.
375 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.  - Butyrate kinase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: ATP + butanoate = ADP + butanoyl phosphate
Bound ligand (Het Group name = FMT)
matches with 50.00% similarity
Bound ligand (Het Group name = ACP)
matches with 81.00% similarity
+ butanoyl phosphate
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     intracellular   2 terms 
  Biological process     metabolic process   2 terms 
  Biochemical function     nucleotide binding     6 terms  


J Bacteriol 191:2521-2529 (2009)
PubMed id: 19201797  
Crystal structure of butyrate kinase 2 from Thermotoga maritima, a member of the ASKHA superfamily of phosphotransferases.
J.Diao, M.S.Hasson.
The enzymatic transfer of phosphoryl groups is central to the control of many cellular processes. One of the phosphoryl transfer mechanisms, that of acetate kinase, is not completely understood. Besides better understanding of the mechanism of acetate kinase, knowledge of the structure of butyrate kinase 2 (Buk2) will aid in the interpretation of active-site structure and provide information on the structural basis of substrate specificity. The gene buk2 from Thermotoga maritima encodes a member of the ASKHA (acetate and sugar kinases/heat shock cognate/actin) superfamily of phosphotransferases. The encoded protein Buk2 catalyzes the phosphorylation of butyrate and isobutyrate. We have determined the 2.5-A crystal structure of Buk2 complexed with (beta,gamma-methylene) adenosine 5'-triphosphate. Buk2 folds like an open-shelled clam, with each of the two domains representing one of the two shells. In the open active-site cleft between the N- and C-terminal domains, the active-site residues consist of two histidines, two arginines, and a cluster of hydrophobic residues. The ATP binding region of Buk2 in the C-terminal domain consists of abundant glycines for nucleotide binding, and the ATP binding motif is similar to those of other members of the ASKHA superfamily. The enzyme exists as an octamer, in which four disulfide bonds form between intermolecular cysteines. Sequence alignment and structure superposition identify the simplicity of the monomeric Buk2 structure, a probable substrate binding site, the key residues in catalyzing phosphoryl transfer, and the substrate specificity differences among Buk2, acetate, and propionate kinases. The possible enzyme mechanisms are discussed.

Literature references that cite this PDB file's key reference

  PubMed id Reference
20048057 M.Julotok, A.K.Singh, C.Gatto, and B.J.Wilkinson (2010).
Influence of fatty acid precursors, including food preservatives, on the growth and fatty acid composition of Listeria monocytogenes at 37 and 10degreesC.
  Appl Environ Microbiol, 76, 1423-1432.  
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