Computational Insights into Copper Resistance-Associated P-type ATPase and HMA5 in Aspergillus awamori

AbstractCopper homeostasis is crucial for cellular function, and Aspergillus awamori employs CopperResistance-Associated P-type ATPase and Probable Copper-Transporting ATPase HMA5 forcopper ion transport and resistance mechanisms. This study integrates whole-genome analysis,homology modeling, molecular docking, and Ramachandran plot analysis to investigate thestructural and functional properties of these proteins.BLAST analysis identified highly conserved copper resistance genes, with P-type ATPase andHMA5 exhibiting sequence identities of 92% and 89%, respectively. Homology modelingrevealed higher structural stability in P-type ATPase (TM-score: 0.91, RMSD: 1.7 Å) comparedto HMA5 (TM-score: 0.88, RMSD: 1.9 Å), suggesting greater structural flexibility in HMA5 dueto cysteine-rich metal-binding motifs. Ramachandran plot analysis validated the models,confirming over 90% of residues in favored and allowed regions.Molecular docking analysis showed P-type ATPase had stronger copper-binding affinity (-9.2kcal/mol) compared to HMA5 (-8.7 kcal/mol), with binding localized to the ATP-binding regionand transmembrane domain. In contrast, HMA5 exhibited broader binding capabilities in themetal-binding domain, supporting its role in multi-metal ion coordination.These findings indicate that P-type ATPase is the primary copper transporter, while HMA5functions as a flexible metal-binding protein. This study enhances the understanding of fungalcopper homeostasis and provides insights for bioremediation and industrial biotechnologyapplications.