PvdF of pyoverdin biosynthesis is a structurally unique N10-formyltetrahydrofolate-dependent formyltransferase

Arch Biochem Biophys. 2019 Mar 30:664:40-50. doi: 10.1016/j.abb.2019.01.028. Epub 2019 Jan 26.

Abstract

The hydroxyornithine transformylase from Pseudomonas aeruginosa is known by the gene name pvdF, and has been hypothesized to use N10-formyltetrahydrofolate (N10-fTHF) as a co-substrate formyl donor to convert N5-hydroxyornithine (OHOrn) to N5-formyl- N5-hydroxyornithine (fOHOrn). PvdF is in the biosynthetic pathway for pyoverdin biosynthesis, a siderophore generated under iron-limiting conditions that has been linked to virulence, quorum sensing and biofilm formation. The structure of PvdF was determined by X-ray crystallography to 2.3 Å, revealing a formyltransferase fold consistent with N10-formyltetrahydrofolate dependent enzymes, such as the glycinamide ribonucleotide transformylases, N-sugar transformylases and methionyl-tRNA transformylases. Whereas the core structure, including the catalytic triad, is conserved, PvdF has three insertions of 18 or more amino acids, which we hypothesize are key to binding the OHOrn substrate. Steady state kinetics revealed a non-hyperbolic rate curve, promoting the hypothesis that PvdF uses a random-sequential mechanism, and favors folate binding over OHOrn.

Keywords: Formyltransferase; N(5)-formyl-N(5)-hydroxyornithine; N(5)-hydroxyornithine; PvdF; Pyoverdin; Transformylase.

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

  • Folic Acid / metabolism
  • Formyltetrahydrofolates / metabolism*
  • Hydroxymethyl and Formyl Transferases / chemistry*
  • Hydroxymethyl and Formyl Transferases / metabolism*
  • Models, Molecular
  • Oligopeptides / biosynthesis*
  • Protein Conformation
  • Pseudomonas aeruginosa / enzymology

Substances

  • Formyltetrahydrofolates
  • Oligopeptides
  • pyoverdin
  • Folic Acid
  • Hydroxymethyl and Formyl Transferases