Crystal structure of the GDSL family esterase EstL5 in complex with PMSF reveals a branch channel of the active site pocket  

作　　者：Runsha Chen Xuechun Gao Ting Nie Jinhong Wu Lin Wang Ali Osman Yan Feng Xianghong Li Yong Zhang 

机构地区：[1]School of Food and Bioengineering,Changsha University of Science&Technology,Changsha 410004,China [2]State Key Laboratory of Microbial Metabolism,Joint International Research Laboratory of Metabolic and Developmental Sciences,School of Life Sciences and Biotechnology,Shanghai Jiao Tong University,Shanghai 200240,China [3]Department of Food Science and Technology,School of Agriculture and Biology,Shanghai Jiao Tong University,Shanghai 200024,China [4]Gastro Endoscopy Center,Shanghai Children’s Hospital,School of Medicine,Shanghai Jiao Tong University,Shanghai 200062,China [5]Biochemistry Department,Faculty of Agriculture,Zagazig University,Zagazig,Egypt

出　　处：《Acta Biochimica et Biophysica Sinica》2023年第11期1833-1839,共7页生物化学与生物物理学报（英文版）

基　　金：supported by the grants from the National Key Research and Development Program of China (No.2020YFA0907702);the National Natural Science Foundation of China (Nos.32261143736 and 31770846);the Key Research and Development Project of Hunan Province (No.2022NK2032).

摘　　要：Esterases/lipases from the GDSL family have potential applications in the hydrolysis and synthesis of important esters of pharmaceutical,food,and biotechnical interests.However,the structural and functional understanding of GDSL enzymes is still limited.Here,we report the crystal structure of the GDSL family esterase EstL5 complexed with PMSF at 2.34Åresolution.Intriguingly,the PMSF binding site is not located at the active site pocket but is situated in a surface cavity.At the active site,we note that there is a trapped crystallization solvent 1,6-hexanediol,which mimics the bound ester chain,allowing for further definition of the active site pocket of EstL5.The most striking structural feature of EstL5 is the presence of a unique channel,which extends approximately 18.9Å,with a bottleneck radius of 6.8Å,connecting the active-site pocket and the surface cavity.Replacement of Ser205 with the bulk aromatic residue Trp or Phe could partially block the channel at one end and perturb its access.Reduced enzymatic activity is found in the EstL5 S205W and EstL5 S205F mutants,suggesting the functional relevance of the channel to enzyme catalysis.Our study provides valuable information regarding the properties of the GDSL-family enzymes for designing more efficient and robust biocatalysts.

关 键 词：GSDL esterase PMSF cavity CHANNEL crystal structure 

分 类 号：O62[理学—有机化学]