Structural Basis for Cyclopropanation by a Unique Enoyl-Acyl Carrier Protein Reductase

Dheeraj Khare; Wendi A Hale; Ashootosh Tripathi; Liangcai Gu; David H Sherman; William H Gerwick; Kristina Håkansson; Janet L Smith

doi:10.1016/j.str.2015.09.013

Structural Basis for Cyclopropanation by a Unique Enoyl-Acyl Carrier Protein Reductase

Structure. 2015 Dec 1;23(12):2213-2223. doi: 10.1016/j.str.2015.09.013. Epub 2015 Oct 29.

Authors

Dheeraj Khare¹, Wendi A Hale², Ashootosh Tripathi¹, Liangcai Gu³, David H Sherman⁴, William H Gerwick⁵, Kristina Håkansson², Janet L Smith⁶

Affiliations

¹ Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA.
² Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA.
³ Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA; Department Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109-1065, USA.
⁴ Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA; Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055, USA; Department Medicinal Chemistry, University of Michigan, Ann Arbor, MI 48109-1065, USA; Department Microbiology & Immunology, University of Michigan, Ann Arbor, MI 48109-5620, USA.
⁵ Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, San Diego, CA 92093, USA.
⁶ Life Sciences Institute, University of Michigan, 210 Washtenaw Avenue, Ann Arbor, MI 48109, USA; Department Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-0600, USA. Electronic address: janetsmith@umich.edu.

Abstract

The natural product curacin A, a potent anticancer agent, contains a rare cyclopropane group. The five enzymes for cyclopropane biosynthesis are highly similar to enzymes that generate a vinyl chloride moiety in the jamaicamide natural product. The structural biology of this remarkable catalytic adaptability is probed with high-resolution crystal structures of the curacin cyclopropanase (CurF ER), an in vitro enoyl reductase (JamJ ER), and a canonical curacin enoyl reductase (CurK ER). The JamJ and CurK ERs catalyze NADPH-dependent double bond reductions typical of enoyl reductases (ERs) of the medium-chain dehydrogenase reductase (MDR) superfamily. Cyclopropane formation by CurF ER is specified by a short loop which, when transplanted to JamJ ER, confers cyclopropanase activity on the chimeric enzyme. Detection of an adduct of NADPH with the model substrate crotonyl-CoA provides indirect support for a recent proposal of a C2-ene intermediate on the reaction pathway of MDR enoyl-thioester reductases.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Amino Acid Sequence
Bacterial Proteins / chemistry*
Bacterial Proteins / metabolism
Cyclopropanes / metabolism*
Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / chemistry*
Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) / metabolism
Molecular Sequence Data
Thiazoles / metabolism

Substances

Bacterial Proteins
Cyclopropanes
Thiazoles
curacin A
Enoyl-(Acyl-Carrier-Protein) Reductase (NADH)

Associated data

PDB/5DOV
PDB/5DOZ
PDB/5DP1
PDB/5DP2

Abstract

Publication types

MeSH terms

Substances

Associated data

Grants and funding