Corrinoids, represented by vitamin B12 are the most complicated, nonpolymeric macromolecules produced in nature. Serving as the requisite prosthetic group for many proteins, corrinoids play a key role in maintaining basic cellular activities such as DNA biosynthesis and methionine biosynthesis. The chemical structures of corrinoids are complicated but also conserved. The major difference among corrinoids is their lower base structure.
Up to date, sixteen different lower bases have been discovered, but the correlation between the lower bases and corrinoid functions are not well understood.
Prof Jun Yan, the principal investigator of Young Innovation Research Team of Environment Pollution and Remediation, CAS key Lab of Pollution Ecology and Environmental Engineering, and the group leader of Microbial Ecology in Polluted Environment in the Institute of Applied Ecology, has found different vitamin B12 analogues seriously affect the cell growth and dechlorination activity of organohalide-respiring bacteria (OHRB), and demonstrated that corrinoid functions are dependent on their lower base structures.
In an international research effort, Prof Jun Yan teamed with Prof Frank Löffler from the University of Tennessee and Oak Ridge National Lab, USA, and Prof Elizabeth Edwards from the University of Toronto, Canada, to characterize the corrinoids produced in diverse OHRB.
A novel corrinoid, which is named purinyl-cobamide with unsubstituted purine as the lower base, was discovered as the native corrinoid synthesized in the tetrachloroethene-dechlorinating Desulfitobacterium.
This work developed an innovative approach by employing non-denaturing blue native gel electrophoresis and proteomics analysis to directly recover purinyl-cobamide from catalytically active tetrachlorethene reductive dehalogenase, demonstrating that purinyl-cobamide serves as the native prosthetic group for the tetrachlorethene reductive dehalogenase to catalyze the reductive dechlorinate reaction.
The results expanded corrinoid structural diversity and assigned unsubstituted purine a biological function.
This discovery has potential to enhance the efficacy of current bioremediation approaches, plus it could open new opportunities to affect the progression of certain human diseases.
This work was on-line published in Nature Chemical Biology (November 2017) entitled as “Purinyl-cobamide Is a Native Prosthetic Group of Reductive Dehalogenase”.
Email: yueqian@iae.ac.cn
Publication Name:YAN Jun et al.
