A cryptic long-chain 3-ketoacyl-ACP synthase in the Pseudomonas putida F1 unsaturated fatty acid synthesis pathway.
A cryptic long-chain 3-ketoacyl-ACP synthase in the Pseudomonas putida F1 unsaturated fatty acid synthesis pathway.
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DOI：
10.1016/j.jbc.2021.100920
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发表时间：
2021-08
期刊：
影响因子：
--
通讯作者：
Cronan JE
中科院分区：
文献类型：
--
作者：
Dong H;Ma J;Chen Q;Chen B;Liang L;Liao Y;Song Y;Wang H;Cronan JE
恶臭假单胞菌F1基因组包含5个编码3-酮酰基载体蛋白(ACP)合成酶的基因。其中四个被注释为编码FabF(3-酮酰基-ACP合成酶II)蛋白，第五个被注释为编码FabB(3-酮酰基-ACP合成酶I)蛋白。其中一种FabF蛋白FabF2在天然宿主中的表达是隐蔽的，只有当控制FabF2转录的抑制子被灭活时，它才具有生理重要性。当去抑制时，FabF2可以在功能上取代FabB，而当由外源启动子表达时，具有较弱的FabF活性。对高效表达的大肠杆菌FabB和FabF突变株的互补实验表明，P.putida FabF1恢复了E.ColiFabF的功能，Fabb恢复了E.ColiFabB的功能，FabF2恢复了E.ColiFabF和Fabb的功能。缺失的P.putidaΔFabF1菌株在顺式疫苗酸的合成方面几乎完全缺陷，而ΔFabb菌株是一种不饱和脂肪酸(UFA)缺陷型营养缺陷体，在没有UFA补充的情况下积累了高水平的自发抑制物。这是由于FabF2的表达增加，绕过了FabB的丢失，这是因为与FabF2编码的同一操纵子中的调节因子Pput_2425失活。高水平的不饱和脂肪酸补充降低了自发抑制物的积累，而通过恶臭假单胞菌β氧化途径的竞争增加了抑制物的积累。ΔFabbΔFabF2菌株是一个稳定的不饱和脂肪酸营养缺陷体，说明抑制因子的积累需要FabF2的功能。然而，在低浓度不饱和脂肪酸的补充下，ΔFabF2ΔPput2425双突变株在低不饱和脂肪酸浓度下仍积累了抑制物。
The Pseudomonas putida F1 genome contains five genes annotated as encoding 3-ketoacyl-acyl carrier protein (ACP) synthases. Four are annotated as encoding FabF (3-ketoacyl-ACP synthase II) proteins, and the fifth is annotated as encoding a FabB (3-ketoacyl-ACP synthase I) protein. Expression of one of the FabF proteins, FabF2, is cryptic in the native host and becomes physiologically important only when the repressor controlling fabF2 transcription is inactivated. When derepressed, FabF2 can functionally replace FabB, and when expressed from a foreign promoter, had weak FabF activity. Complementation of Escherichia coli fabB and fabF mutant strains with high expression showed that P. putida fabF1 restored E. coli fabF function, whereas fabB restored E. coli fabB function and fabF2 restored the functions of both E. coli fabF and fabB. The P. putida ΔfabF1 deletion strain was almost entirely defective in synthesis of cis-vaccenic acid, whereas the ΔfabB strain is an unsaturated fatty acid (UFA) auxotroph that accumulated high levels of spontaneous suppressors in the absence of UFA supplementation. This was due to increased expression of fabF2 that bypasses loss of fabB because of the inactivation of the regulator, Pput_2425, encoded in the same operon as fabF2. Spontaneous suppressor accumulation was decreased by high levels of UFA supplementation, whereas competition by the P. putida β-oxidation pathway gave increased accumulation. The ΔfabB ΔfabF2 strain is a stable UFA auxotroph indicating that suppressor accumulation requires FabF2 function. However, at low concentrations of UFA supplementation, the ΔfabF2 ΔPput_2425 double-mutant strain still accumulated suppressors at low UFA concentrations.
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影响因子：
5.2
作者：
Schmitz S;Nies S;Wierckx N;Blank LM;Rosenbaum MA
通讯作者：
Rosenbaum MA
影响因子：
3.7
作者：
Zarzycki-Siek J;Norris MH;Kang Y;Sun Z;Bluhm AP;McMillan IA;Hoang TT
通讯作者：
Hoang TT
影响因子：
3.2
作者：
Subramanian, Chitra;Rock, Charles O.;Zhang, Yong-Mei
通讯作者：
Zhang, Yong-Mei
影响因子：
6.2
作者：
Ruth, Katinka;de Roo, Guy;Ren, Qun
通讯作者：
Ren, Qun
DOI：
10.1007/bf02983311
发表时间：
1988-01-01
期刊：
CARLSBERG RESEARCH COMMUNICATIONS
影响因子：
--
作者：
KAUPPINEN, S;SIGGAARDANDERSEN, M;VONWETTSTEINKNOWLES, P
通讯作者：
VONWETTSTEINKNOWLES, P