Figure 2.

Crystal structure of EndoS2 with high-mannose glycan. (a) Structure of a high-mannose (man₉) N-glycan, with annotations for the parts used for crystallization (black box), and the parts unambiguously identified in the crystal structure (blue box). (b) Overall structure of the glycan bound within the active site crevasse of the GH domain. Annotation of GH domain loops for EndoS2 is colored. (c) Composite omit map of electron density surrounding the high-mannose glycan: blue mesh, 2Fo-Fc contoured to 1σ, carved to 1.8 Å surrounding the full glycan; green mesh, positive density (Fo–Fc) contoured to 3σ, carved to 5 Å surrounding the α6 antenna; red mesh, negative density (Fo–Fc) contoured to 3σ, carved to 5 Å surrounding the α6 antenna. Arrows indicate the attachment sites for the remaining two mannose residues. (d) Key residues of EndoS2 interacting with HM product are colored in orange.