BRC Science Highlight Discovery of a new type of bacterial enzyme able to cleave bonds in lignin Objective Expand our knowledge of enzymes that cleave β-aryl ether bonds, the most abundant linkage in lignin. Approach Identify glutathione S-transferase (GST) enzymes required to cleave β-aryl ether bonds in Novosphingobium aromaticivorans. Describe the properties and phylogenetic distribution of a newly discovered class of β-etherase GSTs. Results/Impacts A newly discovered heterodimeric β(R)-aryl etherase GST (BaeAB) is catalytically comparable to – or more efficient than – other known enzymes. The subunits of this β-etherase are phylogenetically distinct from each other and from those in other reported β-etherases. Understanding these enzymes will inform new strategies for processing lignin into commodity chemicals. Notes: text Title again: Text 1-2 sentence summary? Phylogenetic tree of GSTs known or predicted to catalyze reactions involved in the sphingomonad pathway for breaking the β-aryl ether bond. Kontur, W. S. et al. “A heterodimeric glutathione S-transferase that stereospecifically breaks lignin’s β(R)-aryl ether bond reveals the diversity of bacterial β-etherases.” Journal of Biological Chemistry 294, 1877-1890 (2019) [DOI: 10.1074/jbc.RA118.006548]. GLBRC February 2019