Molecular Basis of BioJ, a Unique Gatekeeper in Bacterial Biotin Synthesis.
Wei, W., Guan, H., Zhu, T., Zhang, S., Fan, C., Ouyang, S., Feng, Y.(2019) iScience 19: 796-808
- PubMed: 31494495 
- DOI: https://doi.org/10.1016/j.isci.2019.08.028
- Primary Citation of Related Structures:  
6K1T - PubMed Abstract: 
Biotin is an indispensable cofactor in the three domains of life. The unusual virulence factor BioJ of Francisella catalyzes the formation of pimeloyl-ACP, an intermediate in biotin synthesis. Here, we report the 1.58 Å crystal structure of BioJ, the enzymatic activity of which is determined with the in vitro reconstituted reaction and biotin bioassay in vivo. Unlike the paradigm BioH, BioJ displays an atypical α/β-hydrolase fold. A structurally conserved catalytic triad (S151, D248, and H278) of BioJ is functionally defined. A proposed model for BioJ catalysis involves two basic residues-rich cavities, of which cavity-1, rather than cavity-2, binds to the ACP moiety of its physiological substrate, pimeloyl-ACP methyl ester. In summary, this finding provides molecular insights into the BioJ gatekeeper of biotin synthesis.
Organizational Affiliation: 
Department of Pathogen Biology & Microbiology and General Intensive Care Unit of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; College of Animal Science, Zhejiang University, Hangzhou 310058, China.