6drh
ADP-ribosyltransferase toxin/immunity pair
Structural highlights
FunctionTRI1_SERP5 Immunity component of a contact-dependent interbacterial competition system (also called effector-immunity systems). Acts as an arginine mono-ADP-ribosylhydrolase, mediating the removal of mono-ADP-ribose attached to arginine residues on proteins. De-ADP-ribosylates FtsZ, is able to act on other proteins as well. Neutralizes the toxic activity of cognate toxin Tre1-Sp. Expression of this protein alone in E.coli partially protects the cells against competition by wild-type S.proteamaculans. Neutralizes Tre1-Sp both by occluding its active site via its N-terminal extension and by hydrolyzing the ADP-ribosyl moiety from FtsZ; the 2 activities are dissociable by mutagenesis.[1] Publication Abstract from PubMedADP-ribosylation of proteins can profoundly impact their function and serves as an effective mechanism by which bacterial toxins impair eukaryotic cell processes. Here, we report the discovery that bacteria also employ ADP-ribosylating toxins against each other during interspecies competition. We demonstrate that one such toxin from Serratia proteamaculans interrupts the division of competing cells by modifying the essential bacterial tubulin-like protein, FtsZ, adjacent to its protomer interface, blocking its capacity to polymerize. The structure of the toxin in complex with its immunity determinant revealed two distinct modes of inhibition: active site occlusion and enzymatic removal of ADP-ribose modifications. We show that each is sufficient to support toxin immunity; however, the latter additionally provides unprecedented broad protection against non-cognate ADP-ribosylating effectors. Our findings reveal how an interbacterial arms race has produced a unique solution for safeguarding the integrity of bacterial cell division machinery against inactivating post-translational modifications. Bifunctional Immunity Proteins Protect Bacteria against FtsZ-Targeting ADP-Ribosylating Toxins.,Ting SY, Bosch DE, Mangiameli SM, Radey MC, Huang S, Park YJ, Kelly KA, Filip SK, Goo YA, Eng JK, Allaire M, Veesler D, Wiggins PA, Peterson SB, Mougous JD Cell. 2018 Oct 8. pii: S0092-8674(18)31249-2. doi: 10.1016/j.cell.2018.09.037. PMID:30343895[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
