Evidence that pyridoxal phosphate modification of lysine residues (Lys-55 and Lys-59) causes inactivation of hydroxymethylbilane synthase (porphobilinogen deaminase)

Biochem J. 1989 Aug 15;262(1):119-24. doi: 10.1042/bj2620119.

Abstract

A recombinant strain of Escherichia coli has been constructed that produces approx. 200 times the amount of hydroxymethylbilane synthase found in wild-type E. coli [Hart, Abell & Battersby (1986) Biochem. J. 240, 273-276]. Enzyme purified from this strain is shown to be permanently inactivated by pyridoxal 5'-phosphate/NaB1H3(3)H1. The inactivation is not complete despite the fact that approx. 1 mol of lysine residues is modified per mol of enzyme. Evidence is gained showing that (a) modification of one of two conserved lysine residues (Lys-55 or Lys-59) results in inactivation of hydroxymethylbilane synthase and (b) these lysine residues are present in or close to the active site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Ammonia-Lyases / antagonists & inhibitors*
  • Binding Sites
  • Escherichia coli / enzymology
  • Hydroxymethylbilane Synthase / antagonists & inhibitors*
  • Lysine / metabolism*
  • Plasmids
  • Protease Inhibitors / metabolism
  • Pyridoxal Phosphate / pharmacology*

Substances

  • Protease Inhibitors
  • Pyridoxal Phosphate
  • Hydroxymethylbilane Synthase
  • Ammonia-Lyases
  • Lysine