In general aldolases tend to have a more limited substrate scope for the donor rather than the acceptor, consequently they are often classified based on their donor selectivity with the acetaldehyde-dependent enzyme DERA being a prime example of this . DERA catalyses the reversible aldol condensation of acetaldehyde and D-glyceraldehyde-3-phosphate and is typically only able to accept a small range of donor analogues, such as propanal or glycolaldehyde, often coming at the cost of significantly reduced activity . A recent report demonstrated that screening a diverse panel of DERAs resulted in activity toward six different aldehydes . Recent work has also involved engineering DERA to expand the activity of the wild-type enzyme, resulting in variants able to catalyze Michael addition of nitromethane to ,β-unsaturated ketones .