Control of Stereoselectivity in Diverse Hapalindole Metabolites is Mediated by Cofactor‐Induced Combinatorial Pairing of Stig Cyclases
作者:Shasha Li、Sean A. Newmister、Andrew N. Lowell、Jiachen Zi、Callie R. Chappell、Fengan Yu、Robert M. Hohlman、Jimmy Orjala、Robert M. Williams、David H. Sherman
DOI:10.1002/anie.201913686
日期:2020.5.18
The stereospecific polycyclic core formation of hapalindoles and fischerindoles is controlled by the Stig cyclases through a three-step cascade involving Cope rearrangement, 6- exo -trig cyclization and a final electrophilic aromatic substitution. Here we report a comprehensive study of all currently annotated Stig cyclases, and reveal that these proteins can assemble into heteromeric complexes induced
Discovery of a Calcium-Dependent Enzymatic Cascade for the Selective Assembly of Hapalindole-Type Alkaloids: On the Biosynthetic Origin of Hapalindole U
作者:Qin Zhu、Xinyu Liu
DOI:10.1002/anie.201703932
日期:2017.7.24
to the discovery of an unprecedented calcium-dependent AmbU1-AmbU4 enzymatic complex for the selective formation of 4. This discovery refuted the intermediacy of 3 and bridged the missing links in the early-stage biosynthesis of ambiguines. This work further established the isomerocyclases involved in the biogenesis of hapalindole-type alkaloids as a new family of calcium-dependent enzymes, where the
A new family of iron-dependent halogenases acts on freestanding substrates
作者:Matthew L Hillwig、Xinyu Liu
DOI:10.1038/nchembio.1625
日期:2014.11
Nonheme iron halogenases, or enzymes that perform oxidative halogenations, exist in a variety of biosynthetic pathways and modify substrates attached to carrier proteins. Biochemical evidence defines a chlorinase that breaks this rule, acting on soluble substrates. Regio- and stereospecific incorporation of a halogen atom to an unactivated sp3 carbon in a freestanding molecule is a challenging transformation that is currently missing in the inventory of enzyme-mediated reactions. Here we report what is to our knowledge the first example of a nonheme iron enzyme (WelO5) in the welwitindolinone biosynthetic pathway that can monochlorinate an aliphatic carbon in 12-epi-fischerindole U and 12-epi-hapalindole C, substrates that are free from peptidyl or acyl carrier protein.
Aliphatic Halogenase Enables Late-Stage C−H Functionalization: Selective Synthesis of a Brominated Fischerindole Alkaloid with Enhanced Antibacterial Activity
作者:Qin Zhu、Matthew L. Hillwig、Yohei Doi、Xinyu Liu
DOI:10.1002/cbic.201500674
日期:2016.3.15
Bromine dominates! The promiscuous aliphatichalogenase WelO5 selectivelybrominated 12‐epi‐fischerindole U through late‐stage enzymatic functionalization of an unactivated sp3 C−H bond, which showed eight times higher antibacterialactivity against the human pathogen Staphylococcus aureus. This approach highlights the promise of enzyme‐mediated late‐stage aliphatic halogenation in tuning the potency