Download MendeleyStructure and activity of AbiQ, a lactococcal endoribonuclease belonging to the type III toxin-antitoxin system.
Samson, J.E., Spinelli, S., Cambillau, C., Moineau, S.(2013) Mol Microbiol 87: 756-768
- PubMed: 23279123
- DOI: https://doi.org/10.1111/mmi.12129
- Primary Citation of Related Structures:
4GLK - PubMed Abstract:
AbiQ is a phage resistance mechanism found on a native plasmid of Lactococcus lactis that abort virulent phage infections. In this study, we experimentally demonstrate that AbiQ belongs to the recently described type III toxin-antitoxin systems. When overexpressed, the AbiQ protein (ABIQ) is toxic and causes bacterial death in a bacteriostatic manner. Northern and Western blot experiments revealed that the abiQ gene is transcribed and translated constitutively, and its expression is not activated by a phage product. ABIQ is an endoribonuclease that specifically cleaves its cognate antitoxin RNA molecule in vivo. The crystal structure of ABIQ was solved and site-directed mutagenesis identified key amino acids for its anti-phage and/or its RNase function. The AbiQ system is the first lactococcal abortive infection system characterized to date at a structural level.
Organizational Affiliation:
Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et génie, Université Laval, Québec, Canada, G1V 0A6.
