This domain is found at the N-terminal end of Trehalose synthase from Pyrococcus horikoshii (TreT) and similar proteins from prokaryotic organisms. TreT synthesises an alpha,alpha-trehalose from nucleoside diphosphate glucose and glucose. This protein has a typical GT-B glycosyltransferase structure with dual beta/alpha/ beta Rossmann-folds. The N-terminal domain shows a core of six beta-strands and seven associated helices [1].

1: Structural insights on the new mechanism of trehalose synthesis by trehalose synthase TreT from Pyrococcus horikoshii. Woo EJ, Ryu SI, Song HN, Jung TY, Yeon SM, Lee HA, Park BC, Park KH, Lee SB; J Mol Biol. 2010;404:247-259. PMID:20888836