6itw

Publication Abstract from PubMed

The type VI secretion system (T6SS) is a novel multiprotein needle-like apparatus that is distributed widely in Gram-negative bacteria. Bacteria harboring T6SSs inject various effectors into both eukaryotic and prokaryotic cells for interspecies competition or virulence-related processes. The toxicities of the effectors can be neutralized by their cognate immunity proteins. Tde1 (Atu4350)-Tdi1 (Atu4351) has recently been characterized as a T6SS effector-immunity pair in the soil bacterium Agrobacterium tumefaciens and the neutralization mechanism remains unknown. Here, the crystal structure of the immunity protein Tdi1 was determined at 2.40 A resolution by the single-wavelength anomalous dispersion method. Structural analysis suggested that it is composed of a GAD-like domain and an inserted DUF1851 domain, and both domains show low structural similarities to known structures. There is a positive groove mainly located in the GAD-like domain that may be associated with nucleotide binding. The structure provides a basis for further study of the positive groove as a potential active site.

Crystal structure of the type VI immunity protein Tdi1 (Atu4351) from Agrobacterium tumefaciens.,Shi L, Gao Z, Zhang T, Zhang H, Dong Y Acta Crystallogr F Struct Biol Commun. 2019 Mar 1;75(Pt 3):153-158. doi:, 10.1107/S2053230X19000815. Epub 2019 Feb 20. PMID:30839288^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.