TY - JOUR

T1 - The bottromycin epimerase BotH defines a group of atypical α/β-hydrolase-fold enzymes

AU - Sikandar, Asfandyar

AU - Franz, Laura

AU - Adam, Sebastian

AU - Santos-Aberturas, Javier

AU - Horbal, Liliya

AU - Luzhetskyy, Andriy

AU - Truman, Andrew W.

AU - Kalinina, Olga V.

AU - Koehnke, Jesko

N1 - Funding Information: We thank the Swiss Light Source (X06DA), the European Synchrotron Radiation Facility (ID23–1 and ID23–2) and Deutsches Elektronen Synchrotron (P11), as well as associated beamline staff, for their support. We thank S. Hirono and H. Gouda for providing the coordinate file of their solution NMR structure of bottromycin A2. J.K. is the recipient of an Emmy Noether Fellowship from the Deutsche Forschungsgemeinschaft (grant no. KO 4116/3–2). We thank K. Niefind and R. Guimaraes da Silva for critical reading of the manuscript and helpful suggestions.

PY - 2020/9/1

Y1 - 2020/9/1

N2 - d-amino acids endow peptides with diverse, desirable properties, but the post-translational and site-specific epimerization of l-amino acids into their d-counterparts is rare and chemically challenging. Bottromycins are ribosomally synthesized and post-translationally modified peptides that have overcome this challenge and feature a d-aspartate (d-Asp), which was proposed to arise spontaneously during biosynthesis. We have identified the highly unusual α/β-hydrolase (ABH) fold enzyme BotH as a peptide epimerase responsible for the post-translational epimerization of l-Asp to d-Asp during bottromycin biosynthesis. The biochemical characterization of BotH combined with the structures of BotH and the BotH–substrate complex allowed us to propose a mechanism for this reaction. Bioinformatic analyses of BotH homologs show that similar ABH enzymes are found in diverse biosynthetic gene clusters. This places BotH as the founding member of a group of atypical ABH enzymes that may be able to epimerize non-Asp stereocenters across different families of secondary metabolites. [Figure not available: see fulltext.].

AB - d-amino acids endow peptides with diverse, desirable properties, but the post-translational and site-specific epimerization of l-amino acids into their d-counterparts is rare and chemically challenging. Bottromycins are ribosomally synthesized and post-translationally modified peptides that have overcome this challenge and feature a d-aspartate (d-Asp), which was proposed to arise spontaneously during biosynthesis. We have identified the highly unusual α/β-hydrolase (ABH) fold enzyme BotH as a peptide epimerase responsible for the post-translational epimerization of l-Asp to d-Asp during bottromycin biosynthesis. The biochemical characterization of BotH combined with the structures of BotH and the BotH–substrate complex allowed us to propose a mechanism for this reaction. Bioinformatic analyses of BotH homologs show that similar ABH enzymes are found in diverse biosynthetic gene clusters. This places BotH as the founding member of a group of atypical ABH enzymes that may be able to epimerize non-Asp stereocenters across different families of secondary metabolites. [Figure not available: see fulltext.].

UR - http://www.scopus.com/inward/record.url?scp=85087006939&partnerID=8YFLogxK

U2 - 10.1038/s41589-020-0569-y

DO - 10.1038/s41589-020-0569-y

M3 - Article

C2 - 32601484

AN - SCOPUS:85087006939

VL - 16

SP - 1013

EP - 1018

JO - Nature chemical biology

JF - Nature chemical biology

SN - 1552-4450

IS - 9

ER -