UDP-L-arabinose mutase (UAM), involved in the biosynthesis of cell wall non-cellulosic polysaccharides, catalyzes the interconversion of UDP-L-arabinopyranose (UDP-Arap) and UDP-L-arabinofuranose (UDP-Araf) (Saqib et al. 2019). At thermodynamic equilibrium, in vitro the ratio of the pyranose form over the furanose form is 90:10. The ratio of the pyranose to furanose forms reached a plateau at 93:7 from both pyranose- and furanose-forming directions. Native rice mutase is believed to exist as a complex composed of several different UAM monomers.
