Substrate Specificity of Acyltransferase Domains for Efficient Transfer of Acyl Groups
Substrate Specificity of Acyltransferase Domains for Efficient Transfer of Acyl Groups
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酰基转移酶结构域的底物特异性，可有效转移酰基
DOI：
10.3389/fmicb.2018.01840
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发表时间：
2018-08
影响因子：
5.2
通讯作者：
Li Yong Quan
中科院分区：
文献类型：
--
作者：
Shen Jie Jie;Chen Fu;Wang Xiao Xuan;Liu Xiao Fang;Chen Xin Ai;Mao Xu Ming;Li Yong Quan
聚酮酶（PKS）的酰基转移酶结构域（AT）对于通过自酰化和转酰化反应将酰基装载到酰基载体蛋白结构域（A）上以产生结构多样的聚酮化合物至关重要。然而，AT和不寻常的酰基单位之间的相互作用特异性很少记录。在Streptomyces tsukubaensis YN 06中，我们发现AT 4FkbB [他克莫司（FK 506）PKS第四模块中的AT]将烯丙基丙二酰（allmal）和乙基丙二酰（ethmal）单元转移到ACP，这被认为分别负责FK 506及其类似物FK 520的产生。AT 4FkbB中的5个残基（Q119 A、L185 I-V186 D-V187 T和F203 L）的突变导致allmal转移效率降低，但ethmal转移比率较高，推测是由于AT 4FkbB的active.site中的Ser 599与allmal单元中的羰基碳之间的亲核攻击较少，如从分子动力学模拟观察到的。此外，ethmalspecific AT中的这五个残基向AT 4FkbB的相应残基的回复突变增加了其与allmal-CoA的结合亲和力。其中，AT 4FkbB的Val 187主要参与对所有氨基酸的识别，而V187 K突变体产生的FK 520比野生型少。因此，我们的研究结果表明，在AT 4FkbB内的五个关键残基是重要的AT功能聚酮化合物的延伸和潜在的靶向生物合成产生所需的产品和消除不需要的类似物。
Acyltransferase domains (ATs) of polyketide synthases (PKSs) are critical for loading of acyl groups on acyl carrier protein domains (A) via self- and trans-acylation reactions, to produce structurally diverse polyketides. However, the interaction specificity between ATs and unusual acyl units is rarely documented. In Streptomyces tsukubaensis YN06, we found that AT4FkbB [an AT in the fourth module of tacrolimus (FK506) PKS] transferred both allylmalonyl (allmal) and emthylmalonyl (ethmal) units to ACPs, which was supposed responsible for the production of both FK506 and its analog FK520, respectively. Mutations of five residues in AT4FkbB (Q119A, L185I-V186D-V187T, and F203L) caused decreased efficiency of allmal transfer, but a higher ratio of ethmal transfer, supposedly due to less nucleophilic attacks between Ser599 in the active.site of AT4FkbB and the carbonyl carbon in the allmal unit, as observed from molecular.dynamics simulations. Furthermore, reverse mutations of these five residues in ethmalspecific ATs to the corresponding residues of AT4FkbB increased its binding affinity to allmal-CoA. Among these residues, Val187 of AT4FkbB mainly contributed to allmal recognition, and V187K mutant produced less FK520 than wild type. Our findings thus suggested that five critical residues within AT4FkbB were important for AT functionality in polyketide extension and potentially for targeting biosynthesis by generating desirable products and eliminating undesirable analogs.
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影响因子：
4.6
作者：
Wang YY;Zhang XS;Luo HD;Ren NN;Jiang XH;Jiang H;Li YQ
通讯作者：
Li YQ
影响因子：
4.4
作者：
S. Pospíšil;P. Sedmera;V. Havlíček;J. Tax
通讯作者：
S. Pospíšil;P. Sedmera;V. Havlíček;J. Tax
阿维菌素模块化聚酮合酶负载酰基转移酶的结构和功能分析
影响因子：
4
作者：
Fen Wang;Yanjie Wang;Junjie Ji;Zhan Zhou;Jingkai Yu;Hua Zhu;Zhiguo Su;Lixin Zhang;Jianting Zheng
通讯作者：
Jianting Zheng
影响因子：
--
作者：
Tang, Yinyan;Chen, Alice Y.;Khosla, Chaitan
通讯作者：
Khosla, Chaitan
DOI：
10.1073/pnas.0601924103
发表时间：
2006-07-25
影响因子：
11.1
作者：
Tang, Yinyan;Kim, Chu-Young;Khosla, Chaitan
通讯作者：
Khosla, Chaitan