1] State Key Laboratory Breeding Base of Marine Genetic Resources, Third Institute of Oceanography, SOA, Xiamen 361005, China [2] Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA, Xiamen 361005, China [3] Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen 361005, China [4] Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Xiamen 361005, China.
Nat Commun. 2014 Dec 12;5:5755. doi: 10.1038/ncomms6755.
Alkane-degrading bacteria are ubiquitous in marine environments, but little is known about how alkane degradation is regulated. Here we investigate alkane sensing, chemotaxis, signal transduction, uptake and pathway regulation in Alcanivorax dieselolei. The outer membrane protein OmpS detects the presence of alkanes and triggers the expression of an alkane chemotaxis complex. The coupling protein CheW2 of the chemotaxis complex, which is induced only by long-chain (LC) alkanes, sends signals to trigger the expression of Cyo, which participates in modulating the expression of the negative regulator protein AlmR. This change in turn leads to the expression of ompT1 and almA, which drive the selective uptake and hydroxylation of LC alkanes, respectively. AlmA is confirmed as a hydroxylase of LC alkanes. Additional factors responsible for the metabolism of medium-chain-length alkanes are also identified, including CheW1, OmpT1 and OmpT2. These results provide new insights into alkane metabolism pathways from alkane sensing to degradation.
在海洋环境中，烷烃降解菌无处不在，但人们对烷烃降解的调控机制知之甚少。本研究探讨了柴油烷烃降解菌 Alcanivorax dieselolei 中的烷烃感知、趋化作用、信号转导、摄取和途径调控。外膜蛋白 OmpS 检测烷烃的存在并触发烷烃趋化作用复合物的表达。趋化作用复合物的偶联蛋白 CheW2 仅被长链（LC）烷烃诱导，向细胞发送信号以触发 Cyo 的表达，从而参与调节负调控蛋白 AlmR 的表达。这种变化反过来又导致 ompT1 和 almA 的表达，分别驱动 LC 烷烃的选择性摄取和羟化。AlmA 被确认为 LC 烷烃的羟化酶。还确定了负责中链长度烷烃代谢的其他因素，包括 CheW1、OmpT1 和 OmpT2。这些结果为从烷烃感知到降解的烷烃代谢途径提供了新的见解。
