SanM catalyzes the formation of 4-pyridyl-2-oxo-4-hydroxyisovalerate in nikkomycin biosynthesis by interacting with SanN
SanM catalyzes the formation of 4-pyridyl-2-oxo-4-hydroxyisovalerate in nikkomycin biosynthesis by interacting with SanN
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SanM 通过与 SanN 相互作用，在尼可霉素生物合成中催化 4-pyridyl-2-oxo-4-羟基异戊酸的形成。
DOI：
10.1016/j.bbrc.2007.07.016
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发表时间：
2007-09-14
影响因子：
3.1
通讯作者：
Tan, Huarong
中科院分区：
文献类型：
--
作者：
Ling, Hongbo;Wang, Guojun;Tan, Huarong
nikkomycin是一种肽基核苷类抗生素，对植物病原真菌和人类病原真菌具有有效的活性。sanM和sanN基因是反色链霉菌尼克霉素生物合成所必需的。在本研究中，通过酵母双杂交和共免疫沉淀法鉴定了SanM和SanN之间的相互作用。此外，对SanM和SanN进行了异源表达和纯化。进一步的生化分析表明，SanM-SanN相互作用对SanM醛缩酶活性至关重要，但对SanN脱氢酶活性无关。在尼克霉素生物合成中，SanM通过与SanN相互作用，将piconaldehyde和2-oxobutyrate转化为4-pyridyl-2-oxo-4-hydroxyisovalerate。稳态动力学分析表明，吡啶醛对SanM的k - M和k(cat)/ k - M分别为123.2 μ M和11.4 mM(-1) s(-1)， 2-氧丁酸对SanM的k - M和k(cat)/ k - M分别为335.6 μ M和4.0 mM(-1) s（-1）。然而，作为脱氢酶的SanN是独立于SanM的。(C) 2007爱思唯尔公司版权所有。
Nikkomycins are peptidyl nucleoside antibiotics with potent activities against phytopathogenic and human pathogenic fungi. The sanM and sanN genes are required for the nikkomycin biosynthesis of Streptomyces ansochromogenes. In the present study, interaction between SanM and SanN was identified by yeast two-hybrid and co-immunoprecipitation assays. Moreover, SanM and SanN were heterologously expressed and purified. Further biochemical assay demonstrated that the SanM-SanN interaction is essential for SanM aldolase activity but not for SanN dehydrogenase activity. SanM converts piconaldehyde and 2-oxobutyrate to 4-pyridyl-2-oxo-4-hydroxyisovalerate in nikkomycin biosynthesis by interacting with SanN. Steady state kinetics analysis revealed that K-m and k(cat)/K-m of SanM are 123.2 mu M and 11.4 mM(-1) s(-1) for picolinaldehyde, while 335.6 mu M and 4.0 mM(-1) s(-1) for 2-oxobutyrate, respectively. However, SanN as a dehydrogenase is independent of SanM. (C) 2007 Elsevier Inc. All rights reserved.