Functional characterization of the HMP-P synthase of Legionella pneumophila (Lpg1565).
Functional characterization of the HMP-P synthase of Legionella pneumophila (Lpg1565).
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DOI：
10.1111/mmi.14622
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发表时间：
2021-04
影响因子：
3.6
通讯作者：
Downs DM
中科院分区：
文献类型：
--
作者：
Paxhia MD;Swanson MS;Downs DM
硫胺素合成中嘧啶部分的产生，2-甲基-4-氨基-5-羟甲基嘧啶磷酸（HMP-P），已被描述为通过酿酒酵母和其他酵母中的Thi 5依赖性途径进行。先前的工作发现ScThi 5在异源环境中功能不佳。在这里，我们报告的细菌直系同源酵母HMP-P合酶（Thi 5）是必要的HMP合成嗜肺军团菌。与ScThi 5不同，LpThi 5在多种生长条件下在肠道沙门氏菌体内发挥作用。蛋白质LpThi 5是结合吡哆醛-5 '-磷酸（PLP）的二聚体，显然没有溶剂暴露的席夫碱。一小部分LpThi 5蛋白与可以转化为HMP的结合分子共纯化。在体内和体外的变体蛋白的分析证实，在细菌和真核直系同源物之间保守的序列基序中的残基调节LpThi 5的功能。HMP-P合成酶（Thi 5）是酵母中焦磷酸硫胺素生物合成的关键酶。来自嗜肺军团菌的Thi 5同源物有助于其天然宿主中的HMP合成，是一种结合吡哆醛-5 '-磷酸并在纯化的蛋白质与铁一起孵育时释放HMP的酶。在酿酒酵母（Saccharomyces cerevisiae）和L.嗜肺菌的功能差异可能反映了酶之间的结构差异或生物宿主之间的代谢差异。
The production of the pyrimidine moiety in thiamine synthesis, 2-methyl-4-amino-5-hydroxymethylpyrimidine phosphate (HMP-P), has been described to proceed through the Thi5-dependent pathway in Saccharomyces cerevisiae and other yeast. Previous work found that ScThi5 functioned poorly in a heterologous context. Here we report a bacterial ortholog to the yeast HMP-P synthase (Thi5) was necessary for HMP synthesis in Legionella pneumophila. Unlike ScThi5, LpThi5 functioned in vivo in Salmonella enterica under multiple growth conditions. The protein LpThi5 is a dimer that binds pyridoxal-5’-phosphate (PLP), apparently without a solvent-exposed Schiff base. A small percentage of LpThi5 protein co-purifies with a bound molecule that can be converted to HMP. Analysis of variant proteins both in vivo and in vitro confirmed that residues in sequence motifs conserved across bacterial and eukaryotic orthologs modulate the function of LpThi5. HMP-P synthase (Thi5) is a critical enzyme in the biosynthesis of thiamine pyrophosphate in yeast. A Thi5 homolog from Legionella pneumophila, which contributes to HMP synthesis in its native host, is an enzyme that binds pyridoxal-5’-phosphate and releases HMP when the purified protein is incubated with iron. In a heterologous system Thi5 from Saccharomyces cerevisiae and L. pneumophila have functional differences that could reflect structural differences between the enzymes or metabolic differences between organismal hosts.
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影响因子：
16.6
作者：
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通讯作者：
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影响因子：
14.9
作者：
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通讯作者：
Bork, Peer
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL