title: Recent advances in understanding the enzymatic reactions of [4+2] cycloaddition and spiroketalization.
abstract: Diels-Alder-like [4+2] cycloaddition and ketalization of dihydroxy ketones are cyclization reactions with different mechanisms that produce characteristic cyclohexene and spiroketal units, respectively. Here, we review newly identified, naturally occurring '[4+2] cycloadditionases' and 'spiroketalases' and reveal several similarities between the two types of enzymes. During catalysis, these enzymes control product stereochemistry or/and enhance the transformation rate. They exhibit convergent evolution of [4+2] cycloaddition or spiroketalization activity, which is likely dependent on interactions of variable protein folds with specialized chemical structures. An understanding of these similarities is expected to allow for establishment of the underlying principles for the application and catalyst design of associated enzymatic reactions in organic chemistry and synthetic biology.
authors: State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
authors: Qingfei
authors: Q
authors: Zheng
authors: State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
authors: Zhenhua
authors: Z
authors: Tian
authors: State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China; Huzhou Center of Bio-Synthetic Innovation, 1366 Hongfeng Road, Huzhou 313000, China. Electronic address: wliu@mail.sioc.ac.cn.
authors: Wen
authors: W
authors: Liu
mesh_terms: D003500:Cyclization; D004798:Enzymes / Q000737:chemistry*
chemical_list: D004798:Enzymes