Fig. 5

X-ray crystal structure of the 3,6-anhydro-d-galactonate cycloisomerase DauB. a Cartoon representation of the octamer of DauB (ZGAL_3156; pdb id 5olc), each chain being colored with a different color. b Cartoon representation of the monomer of ZGAL_3156 (chain A) colored according to a blue-red gradient from N- to C-terminal. c Cartoon representation of the low-resolution structure (2.0 Å) of the monomer of the d-galactaro-1,4-lactone cycloisomerase AtGCI from Agrobacterium tumefaciens (pdb id 4ggb).The α-helices and β-strands are colored in magenta and cyan, respectively. d Cartoon representation of the high-resolution structure (1.6 Å) of the monomer of AtGCI (pdb id 4hpn) with the entire lid domain visible. e and f Zoom view of the catalytic machinery of ZGAL_3156 and AtGCI (pdb id 4hpn), respectively. g and h Zoom view of the substrate binding pocket of ZGAL_3156 and AtGCI (pdb id 4hpn), respectively. The chains h (in orange) and b (cyan) of ZGAL_3156 are shown g. Two equivalent chains of the AtGCI (Cyan and green, respectively) are shown h. The crystal corresponding to 4hpn contains only one molecule per asymmetric unit and the biological octamer of AtGCI was thus generated by the crystallographic symmetry