Analysis of the mecA Gene Conferring Methicillin Resistance in Staphylococcus aureus

This study presents an in-silico analysis of the MecA drug resistance gene from Staphylococcus aureus, the key determinant of methicillin resistance. The complete gene sequence (1,800 bp; GC% = 33.67) was retrieved from NCBI and translated using Expasy tools, resulting in a 600-amino-acid protein with a molecular weight of 76.1 kDa and a theoretical isoelectric point (pI) of 8.70.

Multiple sequence alignment using Clustal Omega revealed 99.2% identity among MecA homologs, confirming its strong evolutionary conservation. The 3D protein model generated by SWISS-MODEL (based on AlphaFold v2 template, GMQE = 0.81, similarity = 60%) indicated a stable monomeric structure preserving the penicillin-binding domain responsible for β-lactam resistance.

Overall, this computational study highlights the structural stability and functional conservation of MecA, providing a theoretical foundation for drug design and inhibitor modeling aimed at combating methicillin-resistant S. aureus (MRSA).