Reactive Enamines and Imines In Vivo: Lessons from the RidA Paradigm

Trends Biochem Sci. 2019 Oct;44(10):849-860. doi: 10.1016/j.tibs.2019.04.011. Epub 2019 May 15.


Metabolic networks are webs of integrated reactions organized to maximize growth and replication while minimizing the detrimental impact that reactive metabolites can have on fitness. Enamines and imines, such as 2-aminoacrylate (2AA), are reactive metabolites produced as short-lived intermediates in a number of enzymatic processes. Left unchecked, the inherent reactivity of enamines and imines may perturb the metabolic network. Genetic and biochemical studies have outlined a role for the broadly conserved reactive intermediate deaminase (Rid) (YjgF/YER057c/UK114) protein family, in particular RidA, in catalyzing the hydrolysis of enamines and imines to their ketone product. Herein, we discuss new findings regarding the biological significance of enamine and imine production and outline the importance of RidA in controlling the accumulation of reactive metabolites.

Keywords: 2-aminoacrylate stress; RidA; enamine/imine metabolism; reactive metabolite.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Amines / chemistry
  • Amines / metabolism*
  • Catalysis
  • Heat-Shock Proteins / chemistry
  • Heat-Shock Proteins / metabolism*
  • Humans
  • Hydrolysis
  • Imines / chemistry
  • Imines / metabolism*
  • Ketones / chemistry
  • Ketones / metabolism
  • Metabolic Networks and Pathways
  • Ribonucleases / chemistry
  • Ribonucleases / metabolism*


  • Amines
  • Heat-Shock Proteins
  • Imines
  • Ketones
  • Ribonucleases
  • RIDA protein, human