Control of secondary metabolism by farX, which is involved in the γ-butyrolactone biosynthesis of Streptomyces lavendulae FRI-5
Control of secondary metabolism by farX, which is involved in the γ-butyrolactone biosynthesis of Streptomyces lavendulae FRI-5
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DOI：
10.1007/s00203-010-0550-3
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发表时间：
2010-03-01
影响因子：
2.8
通讯作者：
Nihira, Takuya
中科院分区：
文献类型：
--
作者：
Kitani, Shigeru;Doi, Masashi;Nihira, Takuya
γ-丁内酯信号系统作为抗生素产生和/或形态分化的重要调控机制广泛分布于链霉菌中。IM-2 [（2 R，3R，1 'R）-2-（1'-羟丁基）-3-羟甲基-γ-丁内酯]是一种γ-丁内酯，在淡紫链霉菌FRI-5中，它关闭d-环丝氨酸的产生，但开启几种核苷抗生素以及蓝色色素的产生。farX是afsA家族基因的成员，其被提出编码参与γ-丁内酯生物合成的酶。farX的破坏导致d-环丝氨酸的过度生产，并取消了核苷抗生素和蓝色色素的生产与IM-2生产的损失。在farX破坏剂中观察到的所有表型变化通过添加外源IM-2而恢复的发现表明，FarX在IM-2产生中起生物合成作用。野生型菌株和farX破坏物之间的转录比较显示，除了已知的基因farR 1和farR 2之外，其他几个基因（farR 4、farD和farE）也受到IM-2的转录调控。此外，farX转录受IM-2控制的事实表明，S. Lauriculae FRI-5具有微调系统以控制γ-丁内酯的产生。
The gamma-butyrolactone signaling system is distributed widely among streptomycetes as an important regulatory mechanism of antibiotic production and/or morphological differentiation. IM-2 [(2R,3R,1'R)-2-(1'-hydroxybutyl)-3-hydroxymethyl-gamma-butanolide] is a gamma-butyrolactone that switches off the production of d-cycloserine but switches on the production of several nucleoside antibiotics as well as blue pigment in Streptomyces lavendulae FRI-5. farX is a member of the afsA-family genes, which are proposed to encode enzymes involved in gamma-butyrolactone biosynthesis. Disruption of farX caused overproduction of d-cycloserine, and abolished production of nucleoside antibiotic and blue pigment with the loss of IM-2 production. The finding that all phenotypic changes observed in the farX disruptant were restored by the addition of exogenous IM-2 suggested that FarX plays a biosynthetic role in IM-2 production. Transcriptional comparison between the wild-type strain and the farX disruptant revealed that, in addition to already known genes farR1 and farR2, several other genes (farR4, farD, and farE) are under the transcriptional regulation of IM-2. Furthermore, the fact that farX transcription is under the control of IM-2 suggested that S. lavendulae FRI-5 has a fine-tuning system to control gamma-butyrolactone production.