Structural and biochemical characterization of a carbohydrate acetylesterase from Sinorhizobium meliloti 1021

• Crystal structure of a carbohydrate acetylesterase (Sm23) was determined.
• Hydrolysis of acetylated substrates by Sm23 and S10A mutant was investigated.
• Immobilized Sm23 exhibited improved stability compared with soluble Sm23.

In many microorganisms, carbohydrate acetylesterases remove the acetyl groups from various types of carbohydrates. Sm23 from Sinorhizobium meliloti is a putative member of carbohydrate esterase family 3 (CE3) in the CAZy classification system. Here, we determined the crystal structure of Sm23 at 1.75 Å resolution and investigated functional properties using biochemical methods. Furthermore, immobilized Sm23 exhibited improved stability compared with soluble Sm23, which can be used for the design of plant cell wall degrading-systems.