Fig. 4: Structure of the human CS polymerase complex CHSY3-CHPF.
From: Structural basis for human chondroitin sulfate chain polymerization
a Cryo-EM map of the heterodimeric CHSY3-CHPF complex. Density covering CHSY3 is shown in orange and CHPF in gray. A UDP molecule is highlighted in blue, and N-glycans are depicted in dark orange. Both proteins contain an N-terminal GT domain with putative D-glucuronic acid transferase (GlcA-T) activity and a C-terminal GT domain with putative N-acetyl-D-galactosamine transferase (GalNAc-T) activity. The complex is shown from three rotated views. b Structural model of the complex, shown in cartoon representation with the same color scheme as in (a). UDP and N-glycans are shown in stick representation. A close-up view shows EM density around UDP and Mn2+ ion at a contour level of 0.125.
