Engineering a bifunctional cellulase toward a third activity — Cex (GH10) and CenA (GH6) fused into one chain.
Cellulose to glucose.
Plant cell walls are the planet's most abundant carbon store. CxnA was engineered to break them down — two real catalytic domains fused into one protein chain.
First touch breaks off cellobiose. Touch it again to split it into glucose — then push the pieces around.
Method
Random mutation.
Ruthless selection.
Mutate — thousands of random variants
Screen — test the colonies picked forward
Select — keep what works
Repeat — the next cycle would start from the candidates found here.
Mechanism
Two real enzymes.
One chain.
Exoglucanase/xylanase; cleaves from chain ends, releasing cellobiose.
Carbohydrate-Binding Module anchors CxnA to the substrate surface, increasing local enzyme concentration.
Endoglucanase. Cleaves internal bonds, creating new chain ends for Cex to attack — the two domains work in relay.
Two confirmed cellulose-degrading activities, fused into a single engineered protein chain.
iDEC 2026