Kramer, Jil-ChristineJil-ChristineKramerBöhringer, NilsNilsBöhringerMettal, UteUteMettalSchäberle, Till FriedrichTill FriedrichSchäberle2024-03-112024-03-112023https://publica.fraunhofer.de/handle/publica/46399810.1016/j.xpro.2023.1025312-s2.0-8517161346137682715Biosynthetic gene clusters of natural products often harbor genes of unknown function, which are difficult to characterize. Here, we present a protocol for the functional analysis in vitro and in vivo of these biosynthetic genes by heterologous expression in E. coli. We describe steps for the expression of genes of interest in an established E. coli strain optimized to heterologously express natural products. We then detail the expression of a His-tagged gene to deduce the specific function of the protein. For complete details on the use and execution of this protocol, please refer to Böhringer et al.enGeneticsMetabolomicsProtein Expression and Purificationjournal article