Structural Basis for the Friedel-Crafts Alkylation in Cylindrocyclophane Biosynthesis

Wang，Hua Qi1; Mou，Shu Bin1; Xiao，Wen1; Zhou，Huan5; Hou，Xu Dong1; Wang，Su Jing1; Wang，Qian1; Gao，Jiali1,4,6; Wei，Zhiyi2,3; Liu，Lijun1,7; Xiang，Zheng1

2022-02-04

10.1021/acscatal.1c04816

ACS Catalysis   影响因子和分区

2155-5435

The Lewis acid-catalyzed Friedel-Crafts alkylation of an aromatic ring with an alkyl halide is extensively used in organic synthesis. However, its biological counterpart was not reported until the elucidation of the cylindrocyclophane biosynthetic pathway in Cylindrospermum licheniforme ATCC 29412 by Balskus and co-workers. CylK is the key enzyme that catalyzes the formation of the cylindrocyclophane scaffold through the Friedel-Crafts alkylation reactions with regioselectivity and stereospecificity. Further research demonstrates that CylK can accept other resorcinol rings and secondary alkyl halides as substrates. To date, the three-dimensional structure of CylK has not been disclosed and the catalytic mechanism remains obscure. Herein we report the crystal structures of CylK alone and complexed with substrate and product analogues. The structures reveal an unprecedented fusion of an RTX-like domain and a seven-bladed β-propeller domain, and the active site architecture that defines the substrate binding mode. Combining the crystal structures, free energy simulations, and the site-directed mutagenesis experiments, we proposed a concerted double-Activation mechanism, which could explain the regioselectivity and stereospecificity of this unprecedented enzymatic alkylation consistently. This work provides a foundation for engineering CylK as a biocatalyst to expand its substrate scope and applications in organic synthesis.

biosynthesis crystal structure cylindrocyclophane Friedel-Crafts alkylation mechanism

SCI ; EI

英语

通讯

WOS:000753081900049

20220611602532

Alkylation ; Binding energy ; Biochemistry ; Biosynthesis ; Catalysis ; Free energy ; Regioselectivity ; Scaffolds ; Substrates

Construction Equipment:405.1 ; Biotechnology:461.8 ; Thermodynamics:641.1 ; Biochemistry:801.2 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Crystal Lattice:933.1.1

2-s2.0-85124143953

Scopus

1.State Key Laboratory of Chemical Oncogenomics,Guangdong Prov. Key Laboratory of Chemical Genomics,School of Chemical Biology and Biotechnology,Peking University Shenzhen Graduate School,Shenzhen,Guangdong,518055,China
2.Department of Biology,School of Life Sciences,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
3.Brain Research Center,Southern University of Science and Technology,Shenzhen,Guangdong,518055,China
4.Institute of Systems and Physical Biology,Shenzhen Bay Laboratory,Shenzhen,Guangdong,518027,China
5.Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai,201204,China
6.Department of Chemistry and Supercomputing Institute,University of Minnesota,Minneapolis,55455,United States
7.Dlx Scientific,Lawrence,66049,United States

Wang，Hua Qi,Mou，Shu Bin,Xiao，Wen,et al. Structural Basis for the Friedel-Crafts Alkylation in Cylindrocyclophane Biosynthesis[J]. ACS Catalysis,2022,12(3):2108-2117.

Wang，Hua Qi.,Mou，Shu Bin.,Xiao，Wen.,Zhou，Huan.,Hou，Xu Dong.,...&Xiang，Zheng.(2022).Structural Basis for the Friedel-Crafts Alkylation in Cylindrocyclophane Biosynthesis.ACS Catalysis,12(3),2108-2117.

Wang，Hua Qi,et al."Structural Basis for the Friedel-Crafts Alkylation in Cylindrocyclophane Biosynthesis".ACS Catalysis 12.3(2022):2108-2117.