Structure and function of the two-component flavin-dependent methanesulfinate monooxygenase within bacterial sulfur assimilation
Structure and function of the two-component flavin-dependent methanesulfinate monooxygenase within bacterial sulfur assimilation
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细菌硫同化中双组分黄素依赖性甲亚磺酸单加氧酶的结构和功能
DOI：
10.1016/j.bbrc.2019.11.008
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发表时间：
2020
影响因子：
3.1
通讯作者：
Dowling, Daniel P.
中科院分区：
文献类型：
--
作者：
Soule, Jess;Gnann, Andrew D.;Gonzalez, Reyaz;Parker, Mackenzie J.;McKenna, Kylie C.;Nguyen, Son V.;Phan, Ngan T.;Wicht, Denyce K.;Dowling, Daniel P.
甲基硫化合物是微生物环境硫的丰富来源，但它们的使用需要氧化还原系统。细菌sfnandmsuoperons含有双组分黄素依赖的单加氧酶，用于二甲砜（DMSO2）的同化：SfnG将DMSO2转化为甲磺酸盐（MSI -）， MsuD将甲磺酸盐（MS -）转化为亚硫酸盐。然而，msi的酶促氧化转化为ms的过程尚未得到证实，msi超操纵子（MsuC）的最后一种酶的功能也尚未确定。我们采用晶体学和生化研究来鉴定来自荧光假单胞菌的mscs的功能。MsuC的晶体结构采用酰基辅酶a脱氢酶折叠，推测其结合位点为黄素和MSI -， MsuC在其氧化还原酶MsuE、FMN和NADH存在下的功能测定证实了MS -的酶促生成。这些研究表明，MsuC将DMSO2转化为msi - MS-in亚硫酸盐生物合成。
Methyl sulfur compounds are a rich source of environmental sulfur for microorganisms, but their use requires redox systems. The bacterialsfnandmsuoperons contain two-component flavin-dependent monooxygenases for dimethylsulfone (DMSO2) assimilation: SfnG converts DMSO2to methanesulfinate (MSI–), and MsuD converts methanesulfonate (MS–) to sulfite. However, the enzymatic oxidation of MSI–to MS–has not been demonstrated, and the function of the last enzyme of themsuoperon (MsuC) is unresolved. We employed crystallographic and biochemical studies to identify the function of MsuC fromPseudomonas fluorescens. The crystal structure of MsuC adopts the acyl-CoA dehydrogenase fold with putative binding sites for flavin and MSI–, and functional assays of MsuC in the presence of its oxidoreductase MsuE, FMN, and NADH confirm the enzymatic generation of MS–. These studies reveal that MsuC converts MSI–to MS–in sulfite biosynthesis from DMSO2.