Figure 2

Overall structure of SsXR. (a) The monomeric structure of SsXR. The monomeric structure of SsXR is presented as a cartoon diagram. α-helices, β-strands, and loops in core domain are distinguished cyan, magenta, and orange colors, respectively, and auxiliary region I, and II (AR-I and AR-II) are distinguished with orange, and green colors, respectively, and labeled. The bound NADPH cofactors and modeled _D-xylose substrates are presented as sphere models with magenta and light blue colors, respectively. The bottom figure is rotated by 90 degree horizontally from the top figure. (b) Putative catalytic mechanism of SsXR. Dashed likes show hydrogen bonds. (c) Size-exclusion chromatography of SsXR. The SsXR samples in condition of 0, 50, 100, and 150 mM NaCl are distinguished with blue, orange, green, and red colors, respectively. The SsXR with 0 and 150 mM NaCl are eluted as a dimeric and monomeric form, respectively. The standard graph was drawn with black color. (a) Indicates void volume and (b–d), € indicate the standard samples of ferritin (440 kDa), conalbumin (75 kDa), carbonic anhydratse (29 kDa), and ribonuclease A (13.7 kDa), respectively.