Exposing enzymes
Autumn 2016
31 October 2016
It was proposed that CSE functioned in the monolignol pathway in Arabidopsis thaliana in 2014, indicating that loss of function of CSE leads to a reduction in lignin content and a small decrease in plant growth, although the phenotypes are much less severe than in those observed with loss of function of the two preceding enzymes in the lignin pathway in Arabidopsis. Since then, the role of CSE in lignin biosynthesis has been questioned in several species, in part through the inability to demonstrate the activity of the enzyme. The pathway via CSE is certainly counter-intuitive, as it involves the cleavage of a thioester linkage and its subsequent re-formation, involving the hydrolysis of an extra molecule of ATP.