Three-dimensional structures of Pseudomonas aeruginosa PvcA and PvcB, two proteins involved in the synthesis of 2-isocyano-6,7-dihydroxycoumarin

J Mol Biol. 2008 Dec 5;384(1):193-205. doi: 10.1016/j.jmb.2008.09.027. Epub 2008 Sep 19.


The pvcABCD operon of Pseudomonas aeruginosa encodes four proteins (PA2254, PA2255, PA2256, and PA2257) that form a cluster that is responsible for the synthesis of a cyclized isocyano derivative of tyrosine. These proteins, which were identified originally as being responsible for a step in the maturation of the chromophore of the peptide siderophore pyoverdine, have been identified recently as belonging to a family of proteins that produce small organic isonitriles. We report that strains harboring a disruption in the pvcA or pvcB genes are able to grow in iron-depleted conditions and to produce pyoverdine. Additionally, we have determined the three-dimensional crystal structures of PvcA and PvcB. The structure of PvcA demonstrates a novel enzyme architecture that is built upon a Rossmann fold. We have analyzed the sequence conservation of enzymes within this family and identified six conserved motifs. These regions of the protein cluster around a putative active site cavity. The structure of the PvcB protein confirms it is a member of the Fe2+/alpha-ketoglutarate-dependent oxygenase family of enzymes. The active site of PvcB is compared to the structures of other family members and suggests that a conformational change to order several loops will accompany the binding of ligands.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Bacterial Proteins / chemistry*
  • Cell Proliferation / drug effects
  • Conserved Sequence
  • Coumarins / chemistry
  • Coumarins / metabolism*
  • Crystallography, X-Ray
  • Culture Media
  • Iron Chelating Agents / pharmacology
  • Molecular Sequence Data
  • Mutation / genetics
  • Oligopeptides / biosynthesis
  • Operon / genetics
  • Protein Structure, Secondary
  • Pseudomonas aeruginosa / chemistry*
  • Pseudomonas aeruginosa / cytology
  • Pseudomonas aeruginosa / genetics
  • Pseudomonas aeruginosa / growth & development
  • Sequence Alignment
  • Static Electricity


  • 2-isocyano-6,7-dihydroxycoumarin
  • Bacterial Proteins
  • Coumarins
  • Culture Media
  • Iron Chelating Agents
  • Oligopeptides
  • pyoverdin