A dimeric form of glycosyltransferase is responsible for its symmetric catalytic reaction
What is it about?
Elaiophylin glycosyltransferase (ElaGT) has been identified as the enzyme responsible for the symmetric glycosylation of Ela, a unique 16-membered symmetric macrodiolide antibiotic. However, the symmetric catalytic mechanism is still unclear in GT. We have shown here that two molecules of ElaGT can form a symmetric homodimer with a continuous acceptor-binding pocket to bind one Ela. ElaGT may utilize this arrangement to allosterically regulate the catalytic center. Interestingly, this dimer interface resembles that of activator-dependent GT.
Why is it important?
Our structures present a novel self-activating model of GT1 that binds the symmetric substrate, which will help us understand the catalytic mechanism of symmetric sugar-transferring and the activator-dependent GTs. Additionally, we provide a new potential regulation site for substrate specificity.