Type III secretion system (T3SS) effector NleE from Escherichia coli is a S-adenosyl-L-methionine (SAM)-dependent methyltransferase that inhibits NF-kappa-B-mediated proinflammatory response in the host. Its structure shows an alpha-beta doubly wound topology with a central three-stranded anti-paralleled beta-sheet sandwiched by alpha-helices. This protein family is predominantly found in Enterobacterales [1].

1: Structure and specificity of the bacterial cysteine methyltransferase effector NleE suggests a novel substrate in human DNA repair pathway. Yao Q, Zhang L, Wan X, Chen J, Hu L, Ding X, Li L, Karar J, Peng H, Chen S, Huang N, Rauscher FJ 3rd, Shao F; PLoS Pathog. 2014;10:e1004522. PMID:25412445