Substrate binding to the cytochrome P450 OleP is coupled to a large open-to-closed transition that remodels the active site. minimizing its exposure to the external solvent. When the aglycone substrate binds. a small empty cavity is formed between the I and G helices. https://www.bekindtopets.com/save-now-Rx-Chorulon-HCG-for-Cattle-save-extra/