PDBsum entry 1fp7

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protein ligands metals links
Ligase PDB id
Protein chains
549 a.a. *
SO4 ×11
Waters ×270
* Residue conservation analysis
PDB id:
Name: Ligase
Title: Monovalent cation binding sites in n10-formyltetrahydrofolat synthetase from moorella thermoacetica
Structure: Formate--tetrahydrofolate ligase. Chain: a, b. Synonym: formyltetrahydrofolate synthetase. Engineered: yes
Source: Moorella thermoacetica. Organism_taxid: 1525. Expressed in: escherichia coli. Expression_system_taxid: 562.
Biol. unit: Tetramer (from PDB file)
3.20Å     R-factor:   0.285     R-free:   0.355
Authors: R.Radfar,A.Leaphart,J.M.Brewer,W.Minor,J.D.Odom
Key ref:
R.Radfar et al. (2000). Cation binding and thermostability of FTHFS monovalent cation binding sites and thermostability of N10-formyltetrahydrofolate synthetase from Moorella thermoacetica. Biochemistry, 39, 14481-14486. PubMed id: 11087401 DOI: 10.1021/bi001577w
30-Aug-00     Release date:   30-Aug-01    
Go to PROCHECK summary

Protein chains
Pfam   ArchSchema ?
P21164  (FTHS_MOOTH) -  Formate--tetrahydrofolate ligase
559 a.a.
549 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     tetrahydrofolate interconversion   3 terms 
  Biochemical function     nucleotide binding     4 terms  


DOI no: 10.1021/bi001577w Biochemistry 39:14481-14486 (2000)
PubMed id: 11087401  
Cation binding and thermostability of FTHFS monovalent cation binding sites and thermostability of N10-formyltetrahydrofolate synthetase from Moorella thermoacetica.
R.Radfar, A.Leaphart, J.M.Brewer, W.Minor, J.D.Odom, R.B.Dunlap, C.R.Lovell, L.Lebioda.
Formyltetrahydrofolate synthetase (FTHFS) from the thermophilic homoacetogen, Moorella thermoacetica, has an optimum temperature for activity of 55-60 degrees C and requires monovalent cations for both optimal activity and stabilization of tetrameric structure at higher temperatures. The crystal structures of complexes of FTHFS with cesium and potassium ions were examined and monovalent cation binding positions identified. Unexpectedly, NH(4)(+) and K(+), both of which are strongly activating ions, bind at a different site than a moderately activating ion, Cs(+), does. Neither binding site is located in the active site. The sites are 7 A apart, but in each of them, the side chain of Glu 98, which is conserved in all known bacterial FTHFS sequences, participates in metal ion binding. Other ligands in the Cs(+) binding site are four oxygen atoms of main chain carbonyls and water molecules. The K(+) and NH(4)(+) binding site includes the carboxylate of Asp132 in addition to Glu98. Mutant FTHFS's (E98Q, E98D, and E98S) were obtained and analyzed using differential scanning calorimetry to examine the effect of these mutations on the thermostability of the enzyme with and without added K(+) ions. The addition of 0.2 M K(+) ions to the wild-type enzyme resulted in a 10 degrees C increase in the thermal denaturation temperature. No significant increase was observed in E98D or E98S. The lack of a significant effect of monovalent cations on the stability of E98D and E98S indicates that this alteration of the binding site eliminates cation binding. The thermal denaturation temperature of E98Q was 3 degrees C higher than that of the wild-type enzyme in the absence of the cation, indicating that the removal of the unbalanced, buried charge of Glu98 stabilizes the enzyme. These results confirm that Glu98 is a crucial residue in the interaction of monovalent cations with FTHFS.

Literature references that cite this PDB file's key reference

  PubMed id Reference
20118378 G.Henderson, G.E.Naylor, S.C.Leahy, and P.H.Janssen (2010).
Presence of novel, potentially homoacetogenic bacteria in the rumen as determined by analysis of formyltetrahydrofolate synthetase sequences from ruminants.
  Appl Environ Microbiol, 76, 2058-2066.  
15866934 S.Hattori, A.S.Galushko, Y.Kamagata, and B.Schink (2005).
Operation of the CO dehydrogenase/acetyl coenzyme A pathway in both acetate oxidation and acetate formation by the syntrophically acetate-oxidizing bacterium Thermacetogenium phaeum.
  J Bacteriol, 187, 3471-3476.  
15848038 W.F.Li, X.X.Zhou, and P.Lu (2005).
Structural features of thermozymes.
  Biotechnol Adv, 23, 271-281.  
14612565 S.Prasad, K.J.Wright, D.Banerjee Roy, L.A.Bush, A.M.Cantwell, and E.Di Cera (2003).
Redesigning the monovalent cation specificity of an enzyme.
  Proc Natl Acad Sci U S A, 100, 13785-13790.  
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