Download MendeleyStructure and Function of the Autolysin SagA in the Type IV Secretion System of Brucella abortus .
Hyun, Y., Baek, Y., Lee, C., Ki, N., Ahn, J., Ryu, S., Ha, N.C.(2021) Mol Cells 44: 517-528
- PubMed: 34112742
- DOI: https://doi.org/10.14348/molcells.2021.0011
- Primary Citation of Related Structures:
7DNP, 7DPY - PubMed Abstract:
A recent genetic study with Brucella abortus revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. The purified SagA fully hydrolyzed the meso-diaminopimelic acid (DAP)-type PGN, showing a higher activity than hen egg-white lysozyme. The PhiA protein exhibiting tetrameric assembly failed to inhibit SagA activity in our experiments. Our findings provide implications for the molecular basis of the SagA-PhiA system of B. abortus . The development of inhibitors of SagA would further contribute to controlling brucellosis by attenuating the function of T4SS, the major virulence factor of Brucella .
Organizational Affiliation:
Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Center for Food and Bioconvergence, CALS, Seoul National University, Seoul 08826, Korea.
