6ox6

Crystal structure of the complex between the Type VI effector Tas1 and its immunity proteinCrystal structure of the complex between the Type VI effector Tas1 and its immunity protein

Structural highlights 6ox6 is a 2 chain structure with sequence from Pseudomonas aeruginosa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.17Å Ligands: , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TSE6_PSEAE Type VI secretion exported toxin that acts as a glycohydrolase on bacterial target cells and degrades the essential dinucleotides NAD(+) and NADP(+), thereby inducing bacteriostasis. The activity resides in the C-terminal region that is initially neutralized by the cognate immunity protein Tsi6. Publication Abstract from PubMed Bacteria have evolved sophisticated mechanisms to inhibit the growth of competitors(1). One such mechanism involves type VI secretion systems, which bacteria can use to inject antibacterial toxins directly into neighbouring cells. Many of these toxins target the integrity of the cell envelope, but the full range of growth inhibitory mechanisms remains unknown(2). Here we identify a type VI secretion effector, Tas1, in the opportunistic pathogen Pseudomonas aeruginosa. The crystal structure of Tas1 shows that it is similar to enzymes that synthesize (p)ppGpp, a broadly conserved signalling molecule in bacteria that modulates cell growth rate, particularly in response to nutritional stress(3). However, Tas1 does not synthesize (p)ppGpp; instead, it pyrophosphorylates adenosine nucleotides to produce (p)ppApp at rates of nearly 180,000 molecules per minute. Consequently, the delivery of Tas1 into competitor cells drives rapid accumulation of (p)ppApp, depletion of ATP, and widespread dysregulation of essential metabolic pathways, thereby resulting in target cell death. Our findings reveal a previously undescribed mechanism for interbacterial antagonism and demonstrate a physiological role for the metabolite (p)ppApp in bacteria. An interbacterial toxin inhibits target cell growth by synthesizing (p)ppApp.,Ahmad S, Wang B, Walker MD, Tran HR, Stogios PJ, Savchenko A, Grant RA, McArthur AG, Laub MT, Whitney JC Nature. 2019 Nov 6. pii: 10.1038/s41586-019-1735-9. doi:, 10.1038/s41586-019-1735-9. PMID:31695193 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 6ox6, resolution 2.17Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image