Crystal structure of the HRG N2 domain. The structure represents a dimeric form of the N2 domain composed of 2 identical chains, A (cyan) and B (magenta). A sequence alignment of rabbit and human N2 domains is shown with secondary structure elements highlighted; β-sheets (arrows) and the α-helix (cylinder). Conserved cysteine residues are shown in red and the N-glycosylated Asn184 residue in blue.