Figure 1. Predicted structure of the Ire1 luminal domain, and the mutations and recombinant proteins used in the present study.

(A) Structure of the proposed yeast Ire1 luminal domain [20]. Subregion I corresponds roughly to aa 25–104, subregion II to aa 105–235, subregion III to aa 236–265, subregion IV to aa 266–447, and subregion V to aa 448–520. The potential N-glycosylation sites and the cysteine residues are marked as N and C respectively. Positions of the conserved sequences indicated by an interspecies sequence alignment [17] are also shown. (B) Positions of the mutations, and structures of the recombinant proteins are presented.