# Reshaping the binding channel of a novel GH113 family β-mannanase from Paenibacillus cineris (PcMan113) for enhanced activity

## TL;DR

Scientists improved a mannan-degrading enzyme from Paenibacillus cineris to enhance its activity for potential commercial use in producing prebiotics.

## Contribution

A novel GH113 β-mannanase variant with enhanced activity and structural insights into its improved performance.

## Key findings

- PcMan113 showed broader substrate spectrum and better performance than other GH113 mannanases.
- The PcMT3 mutant had 4.60-fold higher activity and 5.53-fold higher catalytic efficiency compared to the wild type.
- MD simulations revealed a less flexible and more efficient substrate-binding channel in the mutant.

## Abstract

Endo-β-mannanases are important enzymes for degrading lignocellulosic biomass to generate mannan, which has significant health effects as a prebiotic that promotes the development of gut microbiota. Here, a novel endo-β-mannanase belonging to glycoside hydrolase (GH) family 113 from Paenibacillus cineris (PcMan113) was cloned, expressed and characterized, as one of only a few reported GH113 family β-mannanases. Compared to other functionally and structurally characterized GH113 mannanases, recombinant PcMan113 showed a broader substrate spectrum and a better performance. Based on a structural homology model, the highly active mutant PcMT3 (F110E/N246Y) was obtained, with 4.60- and 5.53-fold increases of enzyme activity (towards KG) and catalytic efficiency (kcat/Km, against M5) compared with the WT enzyme, respectively. Furthermore, molecular dynamics (MD) simulations were conducted to precisely explore the differences of catalytic activity between WT and PcMT3, which revealed that PcMT3 has a less flexible conformation, as well as an enlarged substrate-binding channel with decreased steric hindrance and increased binding energy in substrate recognition. In conclusion, we obtained a highly active variant of PcMan113 with potential for commercial application in the manufacture of manno-oligosaccharides.

The online version contains supplementary material available at 10.1186/s40643-022-00505-7.