Zhang Tianzhen, Zhang Shiqi, Wang Yan, Peng Zhaojun, Xin Bo, Zhong Cheng
Key Laboratory of Industrial Fermentation Microbiology (Ministry of Education), Tianjin University of Science & Technology, Tianjin 300457, People's Republic of China.
Haihe Laboratory of Synthetic Biology, Tianjin 300051, People's Republic of China.
J Agric Food Chem. 2025 Jan 22;73(3):1982-1993. doi: 10.1021/acs.jafc.4c07301. Epub 2025 Jan 10.
Cyclic diguanosine monophosphate (c-di-GMP) is a crucial secondary messenger that regulates bacterial cellulose (BC) synthesis. It is synthesized by diguanylate cyclase (DGC) containing a Gly-Gly-Asp/Glu-Glu-Phe (GGDEF) domain and degraded by phosphodiesterase (PDE) with a Glu-Ala-Leu (EAL) domain. In this work, a systematic analysis of ten GGDEF-EAL tandem domain proteins from CGMCC 2955 assessed their c-di-GMP metabolic functions and effects on BC titer and structure. Of these, five proteins exhibited DGC activity, and five exhibited PDE activity in vitro. GE03 was identified as a bifunctional protein. Most mutant strains deficient in GGDEF-EAL protein showed changes in BC metabolism, motility, and c-di-GMP levels. The combined knockout of identified PDE proteins increased the BC titer by 48.1% compared to the wild type. Overall, our findings advance our understanding of c-di-GMP signaling and its role in BC synthesis, introducing novel concepts and effective strategies for enhancing industrial BC production.
环二鸟苷单磷酸（c-di-GMP）是一种关键的第二信使，可调节细菌纤维素（BC）的合成。它由含有甘氨酸-甘氨酸-天冬氨酸/谷氨酸-谷氨酸-苯丙氨酸（GGDEF）结构域的二鸟苷酸环化酶（DGC）合成，并由具有谷氨酸-丙氨酸-亮氨酸（EAL）结构域的磷酸二酯酶（PDE）降解。在这项工作中，对来自中国普通微生物菌种保藏管理中心2955的十种GGDEF-EAL串联结构域蛋白进行了系统分析，评估了它们的c-di-GMP代谢功能以及对BC滴度和结构的影响。其中，五种蛋白在体外表现出DGC活性，五种表现出PDE活性。GE03被鉴定为一种双功能蛋白。大多数缺乏GGDEF-EAL蛋白的突变菌株在BC代谢、运动性和c-di-GMP水平上表现出变化。与野生型相比，已鉴定的PDE蛋白的联合敲除使BC滴度提高了48.1%。总体而言，我们的研究结果加深了我们对c-di-GMP信号传导及其在BC合成中的作用的理解，为提高工业BC产量引入了新的概念和有效策略。
