Characterization of Intersubunit Communication in the Virginiamycin trans-Acyl Transferase Polyketide Synthase

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• 作者：Jonathan Dorival ; Thibault Annaval ; Fanny Risser ; Sabrina Collin ; Pierre Roblin ; Christophe Jacob ; Arnaud Gruez ; Benjamin Chagot ; Kira J. Weissman
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：March 30, 2016
• 年：2016
• 卷：138
• 期：12
• 页码：4155-4167
• 全文大小：656K
• ISSN：1520-5126

文摘

Modular polyketide synthases (PKSs) direct the biosynthesis of clinically valuable secondary metabolites in bacteria. The fidelity of chain growth depends on specific recognition between successive subunits in each assembly line: interactions mediated by C- and N-terminal “docking domains” (DDs). We have identified a new family of DDs in trans-acyl transferase PKSs, exemplified by a matched pair from the virginiamycin (Vir) system. In the absence of C-terminal partner (VirA ^CDD) or a downstream catalytic domain, the N-terminal DD (VirFG ^NDD) exhibits multiple characteristics of an intrinsically disordered protein. Fusion of the two docking domains results in a stable fold for VirFG ^NDD and an overall protein–protein complex of unique topology whose structure we support by site-directed mutagenesis. Furthermore, using small-angle X-ray scattering (SAXS), the positions of the flanking acyl carrier protein and ketosynthase domains have been identified, allowing modeling of the complete intersubunit interface.