In this experiment, the MCR1 gene enzyme catalytic domain derived from E.coli was cloned and expressed in E.coli expression system. Purified proteins with high purity and good homogeneity were obtained by affinity chromatography, anion exchange chromatography and molecular sieve chromatography. The protein crystals of the enzyme catalyzed region were screened by the method of seating drop and the hanging drop. After collecting x-ray data, the structure of enzyme catalytic region was analyzed by molecular displacement method, and the resolution reached 1.63 angstrom. Four zinc ion signals were detected by the anomalous scattering signal. The structural analysis found that zinc ions was closely related to the surrounding amino acids of Thr285, His465, His466 and His395 , and Thr285 was phosphorylated. After the mutation of Thr285, His465, His466 and His395 to alanine, the resistance of host bacteria to colistin decreased significantly, indicating that the region was closely related to enzyme activity. In this experiment, the structure of MCR1 enzywas analyzed, me active region and the active center of enzyme was identified, which provided useful information for searching for anti MCR1 targeted drugs.
