Crystal structure determination of the halogenase CtcP from Streptomyces aureofaciens.
Yin, L.(2022) Acta Crystallogr F Struct Biol Commun 78: 270-275
- PubMed: 35787554 
- DOI: https://doi.org/10.1107/S2053230X22006586
- Primary Citation of Related Structures:  
7XGB - PubMed Abstract: 
Chlortetracycline (CTC), a derivative of tetracycline (TC), is a broadly used antibiotic that inhibits the synthesis of bacterial proteins by competing with the A-site tRNA on ribosomes. A recent study showed that during the biosynthesis of CTC in Streptomyces aureofaciens, the halogenase CtcP catalyzes the final chlorination reaction and transforms TC into CTC. However, the structure of this fundamental enzyme is still lacking. Here, selenomethionine-derivatized CtcP from S. aureofaciens was overexpressed and purified and its structure was determined at 2.7 Å resolution. The structure of CtcP reveals the conserved monooxygenase domain shared by all flavin-dependent halogenases and a unique C-terminal domain. Although FAD was not observed in the structure, the monooxygenase domain has a conserved FAD-binding pocket and active center. The C-terminal domain displays an α-helical bundle fold, which could contribute to substrate specificity. This work provides a molecular basis for enzyme engineering to improve the industrial production of CTC.
Organizational Affiliation: 
Department of Pathology, Changhai Hospital, The Second Military Medical University, 168 Changhai Road, Shanghai 200433, People's Republic of China.