Stimulation of Staphylococcus aureus Ligase Enzyme by Magnesium Ion

Abstract

Ligases enzymes were discovered as a member of the nucleotidyl transferase family. Here in this paper, DNA
Ligase is extracted from S. aureus works with the cofactor NAD+ to make a phosphodiester bond and reform
between the 3’hydroxyl and 5’phosphate DNA end. Staphylococcus aureus-DNA Ligases Enzyme type A
(SLE-A) contains two essential domains; NTase and OB- fold domain, which are the most essential domains
for the enzyme function. The main aim of the study is to investigate the activity of SLE-A in the presence
of magnesium ion (Mg+2) by evaluating several kinetic parameters on a time course. The result showed that
SLE-A has optimal activity at 500 µM of Mg+2. Furthermore, the low number of Equilibrium Association
Constant (Km value) explains the binding affinity between DNA ligase of Staphylococcus aureus SLE-A
enzyme and Mg+2 ion was very high and sold.