Two radical-dependent mechanisms for anaerobic degradation of the globally abundant organosulfur compound dihydroxypropanesulfonate.Liu, J., Wei, Y., Lin, L., Teng, L., Yin, J., Lu, Q., Chen, J., Zheng, Y., Li, Y., Xu, R., Zhai, W., Liu, Y., Liu, Y., Cao, P., Ang, E.L., Zhao, H., Yuchi, Z., Zhang, Y.
(2020) Proc Natl Acad Sci U S A
- PubMed: 32571930
- DOI: 10.1073/pnas.2003434117
- Structures With Same Primary Citation
- PubMed Abstract:
2( S )-dihydroxypropanesulfonate (DHPS) is a microbial degradation product of 6-deoxy-6-sulfo-d-glucopyranose (sulfoquinovose), a component of plant sulfolipid with an estimated annual production of 10 10 tons. DHPS is also at mill ...
2( S )-dihydroxypropanesulfonate (DHPS) is a microbial degradation product of 6-deoxy-6-sulfo-d-glucopyranose (sulfoquinovose), a component of plant sulfolipid with an estimated annual production of 10 10 tons. DHPS is also at millimolar levels in highly abundant marine phytoplankton. Its degradation and sulfur recycling by microbes, thus, play important roles in the biogeochemical sulfur cycle. However, DHPS degradative pathways in the anaerobic biosphere are not well understood. Here, we report the discovery and characterization of two O 2 -sensitive glycyl radical enzymes that use distinct mechanisms for DHPS degradation. DHPS-sulfolyase (HpsG) in sulfate- and sulfite-reducing bacteria catalyzes C-S cleavage to release sulfite for use as a terminal electron acceptor in respiration, producing H 2 S. DHPS-dehydratase (HpfG), in fermenting bacteria, catalyzes C-O cleavage to generate 3-sulfopropionaldehyde, subsequently reduced by the NADH-dependent sulfopropionaldehyde reductase (HpfD). Both enzymes are present in bacteria from diverse environments including human gut, suggesting the contribution of enzymatic radical chemistry to sulfur flux in various anaerobic niches.
Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, 300072 Tianjin, China.