PDF(Pubmed)
Abstract：
Dimethylsulfoniopropionate (DMSP) is an abundant marine organosulfur compound with roles in stress protection, chemotaxis, nutrient and sulfur cycling and climate regulation. Here we report the discovery of a bifunctional DMSP biosynthesis enzyme, DsyGD, in the transamination pathway of the rhizobacterium Gynuella sunshinyii and some filamentous cyanobacteria not previously known to produce DMSP. DsyGD produces DMSP through its N-terminal DsyG methylthiohydroxybutyrate S-methyltransferase and C-terminal DsyD dimethylsulfoniohydroxybutyrate decarboxylase domains. Phylogenetically distinct DsyG-like proteins, termed DSYE, with methylthiohydroxybutyrate S-methyltransferase activity were found in diverse and environmentally abundant algae, comprising a mix of low, high and previously unknown DMSP producers. Algae containing DSYE, particularly bloom-forming Pelagophyceae species, were globally more abundant DMSP producers than those with previously described DMSP synthesis genes. This work greatly increases the number and diversity of predicted DMSP-producing organisms and highlights the importance of Pelagophyceae and other DSYE-containing algae in global DMSP production and sulfur cycling.
摘要：
二甲基磺丙酸酯（DMSP）是一种丰富的海洋有机硫化合物，具有保护压力的作用，趋化性,养分和硫循环和气候调节。在这里，我们报告了一种双功能DMSP生物合成酶的发现，DsyGD,在根瘤菌synshinyii和一些以前不知道会产生DMSP的丝状蓝细菌的转氨途径中。DsyGD通过其N末端DsyG甲基硫代羟丁酸酯S-甲基转移酶和C末端DsyD二甲基磺羟丁酸酯脱羧酶结构域产生DMSP。系统发育上不同的DsyG样蛋白，叫做DSYE,在各种环境丰富的藻类中发现了具有甲基硫代羟基丁酸酯S-甲基转移酶活性，包括低的混合，高和以前未知的DMSP生产商。含有DSYE的藻类，特别是成华的pelagophyceae物种，与先前描述的DMSP合成基因相比，在全球范围内是更丰富的DMSP生产者。这项工作大大增加了预测的DMSP产生生物的数量和多样性，并强调了Pelagophyceae和其他含DSYE的藻类在全球DMSP生产和硫循环中的重要性。
