Cloning and Analysis of Cadmium Resistant Gene CAD1 of Saccharomyces cerevisiae

Objective:The CAD1 gene was cloned and its structure and function were predicted. It laid a foundation for later research on the detoxification of heavy metal cadmium and the resistance of other toxic substances. Methods:The full-length clone of the CAD1 gene sequence of Saccharomyces cerevisiae BZL06 was performed by PCR,and then the chromosomal location and phylogenetic relationship were analyzed. The primary and secondary structures,tertiary structure,domain and protein interaction of the protein were predicted by online analytical tools such as ExPASy and ProtParam. Results:The CAD1 gene was located on chromosome IV 1318046~1319275;The full length was 1230 bp,encoding 409 amino acids. The phylogenetic analysis indicated that the CAD1 gene of the S. cerevisiae CEN.PK113-7D(EIW11633.1)was the closest one and the homology between them was 99%. The encoded protein was an unstable hydrophilic protein which was metabolically regulated in the nucleus;there was a distinct coiled-coil region,and there was no transmembrane structure. In the prediction of the structure,it was found that the protein mainly contained α-helix and random coil,β-turn and extended chain dispersion distribution;bZIP and PAP1 domains were predicted to be existed;the result of protein interaction analysis showed that there were 9 proteins whose value was more than or equal to 0.7,and the interaction index of SKN7 protein was the highest one(0.937). Conclusion:The results showed that the cloned CAD1 gene was correct,and its encoded protein was structurally unstable and metabolized in the nucleus. It contained bZIP and PAP1 domains,and closely related to the expression of resistance in the overexpression of heavy metal cadmium and other toxicants. It was closely related to the function of SKN7 protein when expressing resistance.