Hybrid Structure of a Dynamic Single-Chain Carboxylase from Deinococcus radiodurans.
Hagmann, A., Hunkeler, M., Stuttfeld, E., Maier, T.(2016) Structure 24: 1227-1236
- PubMed: 27396827 
- DOI: https://doi.org/10.1016/j.str.2016.06.001
- Primary Citation of Related Structures:  
5FIF, 5H80 - PubMed Abstract: 
Biotin-dependent acyl-coenzyme A (CoA) carboxylases (aCCs) are involved in key steps of anabolic pathways and comprise three distinct functional units: biotin carboxylase (BC), biotin carboxyl carrier protein (BCCP), and carboxyl transferase (CT). YCC multienzymes are a poorly characterized family of prokaryotic aCCs of unidentified substrate specificity, which integrate all functional units into a single polypeptide chain. We employed a hybrid approach to study the dynamic structure of Deinococcus radiodurans (Dra) YCC: crystal structures of isolated domains reveal a hexameric CT core with extended substrate binding pocket and a dimeric BC domain. Negative-stain electron microscopy provides an approximation of the variable positioning of the BC dimers relative to the CT core. Small-angle X-ray scattering yields quantitative information on the ensemble of Dra YCC structures in solution. Comparison with other carrier protein-dependent multienzymes highlights a characteristic range of large-scale interdomain flexibility in this important class of biosynthetic enzymes.
Organizational Affiliation: 
Department Biozentrum, University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.