PDBsum entry 3zug

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Transferase PDB id
Protein chains
335 a.a.
SO4 ×4
Waters ×337
PDB id:
Name: Transferase
Title: E268d mutant of fad synthetase from corynebacterium ammoniag
Structure: Riboflavin biosynthesis protein ribf. Chain: a, b. Synonym: riboflavin kinase, flavokinase, fmn adenylyltransf fad pyrophosphorylase, fad synthase. Engineered: yes. Mutation: yes
Source: Corynebacterium ammoniagenes. Organism_taxid: 1697. Expressed in: escherichia coli. Expression_system_taxid: 469008.
2.05Å     R-factor:   0.197     R-free:   0.229
Authors: B.Herguedas,M.Martinez-Julvez,A.Serrano,M.Medina
Key ref: A.Serrano et al. (2013). Key residues at the riboflavin kinase catalytic site of the bifunctional riboflavin kinase/FMN adenylyltransferase from Corynebacterium ammoniagenes. Cell Biochem Biophys, 65, 57-68. PubMed id: 22892871
19-Jul-11     Release date:   01-Aug-12    
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Protein chains
Pfam   ArchSchema ?
Q59263  (RIBF_CORAM) -  Riboflavin biosynthesis protein RibF
338 a.a.
335 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.  - Riboflavin kinase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: ATP + riboflavin = ADP + FMN
+ riboflavin
      Cofactor: Magnesium or zinc or manganese
   Enzyme class 2: E.C.  - Fad synthetase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: ATP + FMN = diphosphate + FAD
= diphosphate
      Cofactor: Magnesium
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     metabolic process   5 terms 
  Biochemical function     catalytic activity     8 terms  


Cell Biochem Biophys 65:57-68 (2013)
PubMed id: 22892871  
Key residues at the riboflavin kinase catalytic site of the bifunctional riboflavin kinase/FMN adenylyltransferase from Corynebacterium ammoniagenes.
A.Serrano, S.Frago, B.Herguedas, M.Martínez-Júlvez, A.Velázquez-Campoy, M.Medina.
Many known prokaryotic organisms depend on a single bifunctional enzyme, encoded by the RibC of RibF gene and named FAD synthetase (FADS), to convert Riboflavin (RF), first into FMN and then into FAD. The reaction occurs through the sequential action of two activities present on a single polypeptide chain where the N-terminus is responsible for the ATP:FMN adenylyltransferase (FMNAT) activity and the C-terminus for the ATP: riboflavin kinase (RFK) activity. Sequence and structural analysis suggest that T208, N210 and E268 at the C-terminus RFK module of Corynebacterium ammoniagenes FADS (CaFADS) might be key during RF phosphorylation. The effect of site-directed mutagenesis on the RFK activity, as well as on substrates and products binding, indicates that T208 and N210 provide the RFK active-site geometry for binding and catalysis, while E268 might be involved in the catalytic step as catalytic base. These data additionally suggest concerted conformational changes at the RFK module of CaFADS during its activity. Mutations at the RFK site also modulate the binding parameters at the FMNAT active site of CaFADS, altering the catalytic efficiency in the transformation of FMN into FAD. This observation supports the hypothesis that the hexameric assembly previously revealed by the crystal structure of CaFADS might play a functional role during catalysis.