Fig. 4From: Engineering of 3-ketosteroid-∆1-dehydrogenase based site-directed saturation mutagenesis for efficient biotransformation of steroidal substratesStructural analysis of the KsdD3-substrate complex model. a Ribbon representation of the KsdD3 overall structure. FAD and AD are shown as yellow and green stick, respectively. b The FAD-binding site. FAD was colored as yellow stick. c The active site of KsdD3. The catalytic residues are shown as cyan stick. d The predicted substrate binding model. The residues are shown as purple stickBack to article page