title: Molecular and genetic basis for early stage structural diversifications in hapalindole-type alkaloid biogenesis.
abstract: Heterologous expressions and purifications of all WelU proteins from the welwitindolinone pathways in Hapalosiphon welwitschii UTEX B1830 and IC-52-3 led to the discovery that WelU1 and WelU3 selectively assemble 12-epi-fischerindole U (2) and 12-epi-hapalindole C (1), respectively, from 3-geranyl 3-isocyanovinyl indolenine (4) via an enzymatic cascade featuring the Cope rearrangement, stereoselective aza-Prins cyclization and regioselective carbocation deposition. In combination with the in vitro characterization of WelU1/WelU3-homolog AmbU4 for the biogenesis of 12-epi-hapalindole U, this study provide a unified view on the origin of the early stage structural diversifications in hapalindole-type alkaloid biosynthesis, post common intermediate 4.
authors.affiliation: Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA. xinyuliu@pitt.edu.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, USA. xinyuliu@pitt.edu.
authors.forename: Xinyu
authors.identifier: http://orcid.org/0000-0002-4493-6076
authors.initials: X
authors.lastname: Liu
mesh_terms: D000470:Alkaloids / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids