Biosynthetic Chlorination of the Piperazate Residue in Kutzneride Biosynthesis by KthP

W. Jiang, J.R. Heemstra, R.R. Forseth, C.S. Neumann, Soraya Manaviazar, F.C. Schroeder, Karl J Hale, C.T. Walsh

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)

Abstract

Kutznerides 2 and 8 of the cyclic hexadepsipeptide family of antifungal natural products from the soil actinomycete Kutzneria sp. 744 contain two sets of chlorinated residues, a 6,7-dichlorohexahydropyrroloindole moiety derived from dichlorotryptophan and a 5-chloropiperazate moiety, as well as a methylcyclopropylglycine residue that may arise from isoleucine via a cryptic chlorination pathway. Previous studies identified KtzD, KtzQ and KtzR as three halogenases in the kutzneride pathway but left no candidate for installing the CS chlorine on piperazate. On the basis of analysis of the complete genome sequence of Kutzneria, we now identify a fourth halogenase in the pathway whose gene is separated from the defined kutzneride cluster by 12 open reading frames. KthP (kutzneride halogenase for piperazate) is a mononuclear nonheme iron halogenase that acts on the piperazyl ring tethered by a thioester linkage to the holo forms of thiolation domains. MS analysis of the protein-bound product confirmed chlorination of the piperazate framework from the (3S)- but not the (3R)-piperazyl-S-pantetheinyl thiolation proteins. After thioesterase-mediated release, nuclear magnetic resonance was used to assign the free imino acid as (3S,5S)-5-chloropiperazate, distinct from the 3S,5R stereoisomer reported in the mature kutznerides. These results demonstrate that a fourth halogenase, KthP, is active in the kutzneride biosynthetic pathway and suggest further processing of the (3S,5S)-5-chloropiperazate during subsequent incorporation into the kutzneride depsipeptide frameworks.
Original languageEnglish
Pages (from-to)6063-6072
Number of pages10
JournalBiochemistry
Volume50
Issue number27
Early online date07 Jun 2011
DOIs
Publication statusPublished - 12 Jul 2011

ASJC Scopus subject areas

  • Biochemistry

Fingerprint Dive into the research topics of 'Biosynthetic Chlorination of the Piperazate Residue in Kutzneride Biosynthesis by KthP'. Together they form a unique fingerprint.

Cite this