https://www.cas.cn/cm/202510/t20251009_5084692.shtml

https://www.nature.com/articles/s41929-025-01413-7

A team at the CAS Institute of Microbiology and from Xiamen University has discovered a metalloisomerase with a new function in catalyzing the oxidative cleavage of hexoses, revealing a sophisticated strategy by Bacillus strains to achieve metabolic balance using a “one enzyme, two functions.”

Art22 is a TIM-barrel enzyme involved in the sugar-moiety modification of the antibiotic aurantinin B (ART B). It activates 4-keto ART B to ART B through rapid isomerization. Additionally, Art22 slowly converts ART B into inactive products through oxidative cleavage of the 3-keto hexopyranose.

Art22 can sequentially complete the isomerization and oxidative cleavage reactions within the same active site, simultaneously fulfilling both “synthesis” and “degradation” roles within the microbiome: promoting the production of antimicrobial molecules to inhibit competing bacteria while also promptly inactivating trace toxic products such as cyclohexane within the cell to protect itself, maintaining a delicate balance.