Mechanisms of feedback inhibition and sequential firing of active sites in plant aspartate transcarbamoylase

Abstract

Aspartate transcarbamoylase acts in de novo pyrimidine biosynthesis and in plants is regulated by feedback inhibition via uridine 5-monophosphate (UMP). Here Bellin et al. describe the structural basis for this feedback inhibition, showing that UMP blocks the active site by binding to a plant specific UMP recognition loop.