Singapore Institute of Food and Biotechnology Innovation, Agency for Science, Technology and Research (A*STAR), Singapore 138669, Singapore.
Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, China.
Biosci Rep. 2022 Oct 28;42(10). doi: 10.1042/BSR20220314.
Sulfoquinovose (SQ, 6-deoxy-6-sulfo-D-glucose) is a sulfo-sugar with a ubiquitous distribution in the environment due to its production by plants and other photosynthetic organisms. Bacteria play an important role in degradation of SQ and recycling of its constituent sulfur and carbon. Since its discovery in 1963, SQ was noted to have a structural resemblance to glucose-6-phosphate and proposed to be degraded through a pathway analogous to glycolysis, termed sulfoglycolysis. Studies in recent years have uncovered an unexpectedly diverse array of sulfoglycolytic pathways in different bacteria, including one analogous to the Embden-Meyerhof-Parnas pathway (sulfo-EMP), one analogous to the Entner-Doudoroff pathway (sulfo-ED), and two involving sulfo-sugar cleavage by a transaldolase (sulfo-TAL) and transketolase (sulfo-TK), respectively, analogous to reactions in the pentose phosphate (PP) pathway. In addition, a non-sulfoglycolytic SQ degradation pathway was also reported, involving oxygenolytic C-S cleavage catalyzed by a homolog of alkanesulfonate monooxygenase (sulfo-ASMO). Here, we review the discovery of these new mechanisms of SQ degradation and lessons learnt in the study of new catabolic enzymes and pathways in bacteria.
磺基奎诺糖（SQ，6-脱氧-6-磺酸-D-葡萄糖）是一种在环境中广泛分布的磺酸糖，由于其由植物和其他光合生物产生。细菌在 SQ 的降解和其组成的硫和碳的再循环中发挥重要作用。自 1963 年发现以来，SQ 被注意到与葡萄糖-6-磷酸具有结构相似性，并被提议通过类似于糖酵解的途径降解，称为磺基糖酵解。近年来的研究揭示了不同细菌中磺基糖酵解途径的惊人多样性，包括类似于 Embden-Meyerhof-Parnas 途径（磺基-EMP）的途径、类似于 Entner-Doudoroff 途径（磺基-ED）的途径，以及两种涉及通过转醛酶（磺基-TAL）和转酮酶（磺基-TK）裂解磺基糖的途径，分别类似于戊糖磷酸（PP）途径中的反应。此外，还报道了一种非磺基糖酵解的 SQ 降解途径，涉及由烷烃磺酸盐单加氧酶（磺基-ASMO）同源物催化的需氧 C-S 裂解。在这里，我们回顾了这些 SQ 降解新机制的发现，以及在细菌中新代谢酶和途径的研究中得到的经验教训。
