Structural analysis of a shrimp thymidylate synthase reveals species-specific interactions with dUMP and raltitrexed  

作　　者：LIU Changshui ZANG Kun LI Shihao LI Fuhua MA Qingjun 

机构地区：[1]Key Laboratory of Experimental Marine Biology,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China [2]Laboratory for Marine Biology and Biotechnology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266000,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China

出　　处：《Journal of Oceanology and Limnology》2020年第6期1891-1899,共9页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(Nos.31572660,31872600);the“1000 Talents Program”,and the Qingdao Innovation Leadership Project(No.18-1-2-12-zhc)。

摘　　要：Thymidylate synthase(TS)is a key enzyme in the de novo biosynthesis of thymidine monophosphate,serving as a well-known drug target in chemotherapy against cancers and infectious diseases.Additional to its clinical value,TS is supposed to be a promising drug target in aquatic-disease control.To facilitate designing pathogen-specific TS inhibitors for shrimp-disease control,we report the crystal structures of TS from Litopenaeus vannamei(LvTS)in the apo form,LvTS-dUMP complex and LvTS-dUMP-raltitrexed complex at 2.27Å,1.54Å,and 1.56Åresolution,respectively.LvTS shares a similar fold with known TSs,existing as a dimer in the crystal.The apo LvTS and LvTS-dUMP take an open conformation,and raltitrexed binding induces structural changes into a closed conformation in LvTS-dUMP-raltitrexed.Compared to those in other known TS-dUMP-raltitrexed complexes with the closed conformation,the C-terminal loop in LvTS-dUMP-raltitrexed shifts its position away from the bound raltitrexed;the distance between C6 of dUMP and Sγof the catalytic cysteine is obviously longer than that in the known TS structures with closed conformations,resembling that in the TS structures with open conformations.Other species-specific interactions with dUMP and raltitrexed are also observed.Therefore,LvTS-dUMP-raltitrexed adopts a loosely closed conformation with structural features intermediate between the closed and the open conformations that were reported in other TSs.Our study provides the first crustcean TS structure,and reveals species-specific interactions between TSs and the ligands,which would facilitate designing pathogen-specific TS inhibitors for shrimp-disease control.

关 键 词：thymidylate synthase(TS) closed conformation deoxyuridine monophosphate(dUMP) thymidine monophosphate(TMP) RALTITREXED Litopenaeus vannamei 

分 类 号：S943[农业科学—水产养殖]