Liu Yongchuang, Ma Feilong, Zhang Hongfei, Chu Cuiwei, Wang Xiaohui, Tang Yuehui, He Jian, Qiu Jiguo, Xu Siqiong, Li Lili
College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou 466001, PR China.
Field Observation and Research Station of Green Agriculture in Dancheng County, Zhoukou 466001, PR China.
Curr Res Microb Sci. 2025 Jul 20;9:100444. doi: 10.1016/j.crmicr.2025.100444. eCollection 2025.
The abundant solute dimethylsulfoniopropionate (DMSP) is crucial in marine ecosystems. In this study, a bacterium, sp. ZS25, capable of completely mineralizing DMSP and producing DMS and acrylate, was isolated. The possible DMSP degradation pathway was primarily identified. The role of DMSP lyases DddY was identified through a combination of genomic comparison, gene knockout and heterologous expression. The and of AsDddY for DMSP were 2.6 mM and 12.7 × 10 s, respectively. Site-directed mutagenesis was employed to examine the influence of specific amino acid residues (Thr131, Asp181, Tyr225, Gly230, Gly250, His263, His265, Glu269, Tyr271, Leu274, Tyr331, and His338) within AsDddY, elucidating their critical roles in the protein's functionality. Bioinformatics analysis revealed 19 distinct cluster order types, while the number of strains with a complete - cluster is limited. Our findings offer novel insights into the mechanisms underlying DMSP biodegradation and enhance our understanding of the diversity of - clusters present in natural bacterial populations.
丰富的溶质二甲基巯基丙酸内盐（DMSP）在海洋生态系统中至关重要。在本研究中，分离出了一种能够将DMSP完全矿化并产生DMS和丙烯酸酯的细菌，即ZS25菌株。初步确定了可能的DMSP降解途径。通过基因组比较、基因敲除和异源表达相结合的方法，确定了DMSP裂解酶DddY的作用。AsDddY对DMSP的Km和kcat分别为2.6 mM和12.7×10 s。采用定点诱变来研究AsDddY内特定氨基酸残基（Thr131、Asp181、Tyr225、Gly230、Gly250、His263、His265、Glu269、Tyr271、Leu274、Tyr331和His338）的影响，阐明它们在蛋白质功能中的关键作用。生物信息学分析揭示了19种不同的簇顺序类型，而具有完整簇的菌株数量有限。我们的研究结果为DMSP生物降解的潜在机制提供了新的见解，并增进了我们对天然细菌群体中簇多样性的理解。
