摘要
Dehydration of serine/threonine residues necessitates the activity of a dehydratase enzyme(domain)during the biosynthesis of RiPP.Recently,it was reported that dehydration in the thioviridamide pathway relies on a distinct dehydratase complex that showcases the activities of a phosphotransferase TvaC for serine/threonine phosphorylation and a lyase TvaD for subsequent phosphate elimination.Herein,we report that dehydration reactions in the pathway of lantibiotic cacaoidin involves a similar dehydratase complex,CaoK/CaoY.Remarkably,this dehydratase complex exhibits flexible enzymatic activity and tolerates significant variations in its substrate peptide sequence.By binding with the leader peptide(LP)sequence of precursor peptide CaoA,the dehydration reactions proceed in a directional manner from the C-terminus of the core peptide(CP)to the N-terminus,and C-terminally truncated variants of CP are acceptable.We show that fusing CaoK to CaoY in a 1:1 molar ratio enables the resulting enzyme CaoYK to exert enhanced dehydration activity.CaoK binds with the LP to improve its own solubility and to ensure the phosphate transfer activity,while CaoY functions in a manner independently of LP.This work advances our understanding of the dehydration process during cacaoidin formation,and provides useful enzymes and methods for the studies of the rapidly emerging RiPPs.
基金
supported in part by grants from the National Key Research and Development Program of China(2022YFC2303100 for L.P and W.L)
the National Natural Science Foundation of China(32030002 and 22193070 for W.L)
the Science and Technology Commission of Shanghai Municipality(20XD1425200 for L.P)
the CAS Youth Interdisciplinary Team(JCTD-2022-10 for L.P).
作者简介
Yanqing Xue,contribute to this work equally;Miao Li,contribute to this work equally;Lifeng Pan,E-mail:panlf@sioc.ac.cn;Wen Liu,E-mail:wliu@sioc.ac.cn。
