4luq
From Proteopedia
Crystal structure of virulence effector Tse3 in complex with neutralizer Tsi3
Structural highlights
FunctionTSE3_PSEAE Toxin secreted by the H1 type VI (H1-T6SS) secretion system into the periplasm of recipient cells. Degrades peptidoglycan via muramidase activity thereby helping itself to compete with other bacteria (PubMed:21776080). To protect itself, the bacterium synthesizes immunity protein Tsi3 that specifically interacts with and inactivates cognate toxin (PubMed:24025333).[1] [2] Publication Abstract from PubMedThe warfare among microbial species as well as between pathogens and hosts is fierce, complicated, and continuous. In Pseudomonas aeruginosa, the muramidase effector Tse3 (Type VI secretion exported 3) can be injected into the periplasm of neighboring bacterial competitors by a Type VI secretion apparatus, eventually leading to cell lysis and death. However, P. aeruginosa protects itself from lysis by expressing immune protein Tsi3 (Type six secretion immunity 3). Here, we report the crystal structure of the Tse3-Tsi3 complex at 1.8 A resolution, revealing that Tse3 possesses one open accessible, goose-type lysozyme-like domain with peptidoglycan hydrolysis activity. Calcium ions bind specifically in the Tse3 active site and are identified to be crucial for its bacteriolytic activity. In combination with biochemical studies, the structural basis of self-protection mechanism of Tsi3 is also elucidated, thus providing an understanding and new insights into the effectors of Type VI secretion system. Structural Insights on the Bacteriolytic and Self-protection Mechanism of Muramidase Effector Tse3 in Pseudomonas aeruginosa.,Li L, Zhang W, Liu Q, Gao Y, Gao Y, Wang Y, Wang DZ, Li Z, Wang T J Biol Chem. 2013 Oct 18;288(42):30607-13. doi: 10.1074/jbc.C113.506097. Epub, 2013 Sep 11. PMID:24025333[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||
