Substrate Specificity of the Nonribosomal Peptide Synthetase PvdD from Pseudomonas aeruginosa

AUTOR(ES)

Ackerley, David F.

FONTE

American Society for Microbiology

RESUMO

Pseudomonas aeruginosa PAO1 secretes a siderophore, pyoverdinePAO, which contains a short peptide attached to a dihydroxyquinoline moiety. Synthesis of this peptide is thought to be catalyzed by nonribosomal peptide synthetases, one of which is encoded by the pvdD gene. The first module of pvdD was overexpressed in Escherichia coli, and the protein product was purified. l-Threonine, one of the amino acid residues in pyoverdinePAO, was an effective substrate for the recombinant protein in ATP-PPi exchange assays, showing that PvdD has peptide synthetase activity. Other amino acids, including d-threonine, l-serine, and l-allo-threonine, were not effective substrates, indicating that PvdD has a high degree of substrate specificity. A three-dimensional modeling approach enabled us to identify amino acids that are likely to be critical in determining the substrate specificity of PvdD and to explore the likely basis of the high substrate selectivity. The approach described here may be useful for analysis of other peptide synthetases.

Documentos Relacionados

• Nucleotide sequence of pvdD, a pyoverdine biosynthetic gene from Pseudomonas aeruginosa: PvdD has similarity to peptide synthetases.
• PchC Thioesterase Optimizes Nonribosomal Biosynthesis of the Peptide Siderophore Pyochelin in Pseudomonas aeruginosa
• The thioesterase domain from a nonribosomal peptide synthetase as a cyclization catalyst for integrin binding peptides
• Iron-regulated transcription of the pvdA gene in Pseudomonas aeruginosa: effect of Fur and PvdS on promoter activity.
• Analysis of Promoters Recognized by PvdS, an Extracytoplasmic-Function Sigma Factor Protein from Pseudomonas aeruginosa