l-2,3-Diaminopropionate: One of the building blocks for the biosynthesis of Zwittermicin A in Bacillus thuringiensis subsp. kurstaki strain YBT-1520

Zwittermicin A (ZwA) is a hybrid polyketide–non-ribosomal peptide that is thought to be biosynthesized from five proposed building blocks, including the 2,3-diaminopropionate. Candidate genes for de novo biosynthesis of 2,3-diaminopropionate, zwa5A and zwa5B, have been identified in a previous study. In this research, zwa5A was interrupted and chemically synthesized 2,3-diaminopropionate was used to feed the zwa5A− mutant. Results showed that feeding with 2,3-diaminopropionate restored the ability of the zwa5A− mutant to produce ZwA. Another non-ribosomal peptide synthase gene, designated orf3, was identified. Amino acid dependent PPi release assay showed that the adenylation domain ZWAA2 of ORF3 acyl-adenylated l-2,3-diaminopropionate effectively. Taken together, it can be concluded that l-2,3-diaminopropionate is indeed one of the building blocks for the biosynthesis of Zwittermicin A.