Two Distinct Aerobic Methionine Salvage Pathways Generate Volatile Methanethiol in Rhodopseudomonas palustris
作者:Anthony R. Miller、Justin A. North、John A. Wildenthal、F. Robert Tabita
DOI:10.1128/mbio.00407-18
日期:2018.5.2
in the presence of oxygen, to salvage sulfur, R. palustris employs two pathways, both of which result in production of volatile methanethiol, a key compound of the global sulfur cycle. When total available sulfur was plentiful, methanethiol was readily released into the environment. However, when sulfur became limiting, methanethiol release decreased, presumably due to methanethiol utilization to regenerate
5'-甲基硫腺苷 (MTA) 是一种死端的含硫代谢物和细胞抑制剂,由 S-腺苷-l-甲硫氨酸依赖性反应产生。最近的研究表明,有多种细菌甲硫氨酸回收途径 (MSP) 可用于 MTA 解毒和硫回收。在这里,通过结合基因缺失和定向代谢物检测研究,我们报告说,在有氧条件下,兼性厌氧细菌沼泽红假单胞菌采用与先前在红色红螺菌中描述的相同的 MTA-类异戊二烯分流器和第二种新型 MSP,两者均生成甲硫醇中间体。额外的 R. palustris 好氧 MSP,一种二羟基丙酮磷酸盐 (DHAP)-甲硫醇分流器,最初将 MTA 转化为 2-(甲硫基) 乙醇和 DHAP。这与最近报道的厌氧乙烯形成 MSP(DHAP-乙烯分流器)的初始步骤相同。有氧 DHAP-甲硫醇分流然后进一步将 2-(甲硫基)乙醇代谢为甲硫醇,其可被 O-乙酰基-1-高丝氨酸硫化氢化酶直接利用以再生甲硫氨酸。这与厌氧 DHAP-乙烯分流相反,后者将