[Tuan-hua David Ho] A unique self-truncation of bacterial GH5 endoglucanases leads to enhanced activity and thermostabilityPOST:
GsCelA is a 368-amino acid endoglucanase secreted by the thermophilic bacterium Geobacillus sp. 70PC53 isolated from a rice straw compost in southern Taiwan. This enzyme belongs to the glycoside hydrolase family 5 (GH5) EGs with a TIM-barrel structure that is common among this type of enzymes. The purified recombinant GsCelA displays unique self-truncation process, resulting in the removal of 53 amino-acid peptide from the C-terminus, leading to higher specific activity and thermostability than the original full-length enzyme. A similar self-truncation/activation process has been observed in at least two other GH5 EGs produced by Gram-positive bacteria. The mechanisms and biological significance of this self-truncation has been explored by the Ho lab.