TrmB is an alpha-glucoside sensing transcriptional regulator. The protein is the transcriptional repressor for gene cluster encoding trehalose/maltose ABC transporter in T.litoralis and P.furiosus [1]. TrmB has lost its DNA binding domain but retained its sugar recognition site. A nonreducing glucosyl residue is shared by all substrates bound to TrmB which suggests that its a common recognition motif [1].

1: Crystal structure of the sugar binding domain of the archaeal transcriptional regulator TrmB. Krug M, Lee SJ, Diederichs K, Boos W, Welte W; J Biol Chem. 2006;281:10976-10982. PMID:16473881