Structure of enzyme domain involved in synthesis of natural products

Janet Smith group (University of Michigan) and collaborators

Janet Smith's group from the University of Michigan used the beamline automounter to screen ~48 crystals in ~4 hrs to solve the structure of the ECH2 domain of CurF from Lyngbya majuscula. CurF ECH₂ is a decarboxylase involved in the introduction of a cyclopropyl ring in the biosynthesis of the natural product curacin A, which is a potent cytotoxic agent. The structure was solved with a 3-wavelength MAD data set using selenomethionine-labeled protein on beamline 23ID-B. The structure demonstrated that CurF ECH₂ has a crotonase fold, and substrate modeling into the active site facilitated testing of active site residues. This new structure has provided insights into β-branching in polyketide synthesis as described in a manuscript submitted for publication.

Figure: View of CurF ECH2 monomer demonstrating crotonase superfamily fold and active site chamber highlighted with red asterisk.

Citation:
Geders, TW, Gu, L, Mowers, JC, Liu, H, Gerwick, WH, Hakansson, K, Sherman, DH, Smith, JL. "Crystal Structure of the ECH₂ Catalytic Domain of CurF from Lyngbya majuscula: Insights into a Decarboxylase Involved in Polyketide Chain β-Branching", J. Biol. Chem. 282 (49), 35954-35963 (2007). DOI: 10.1074/jbc.M703921200.