2.3.1.129 G189S Escherichia coli strain SM101 is deficient in LpxA activity due to a G189S inactivating mutation. Enzymatic activity is restored when the mutant strain is transformed with a wild-type bearing plasmid is inactive 706784 2.3.1.129 G52L/R58L residue tolerance in the beta-helical domain: mutation is tolerated 706784 2.3.1.129 G52V/R58V residue tolerance in the beta-helical domain: mutation is tolerated 706784 2.3.1.129 G52W/R58W residue tolerance in the beta-helical domain: mutation is tolerated 706784 2.3.1.129 G57P/N51P residue tolerance in the beta-helical domain: mutation is not tolerated 706784 2.3.1.129 H122A lower specific activity than wild-type 486258 2.3.1.129 H122N lower specific activity than wild-type 486258 2.3.1.129 H125A H125 is an important residue at the active site its mutation eliminates activity. Mutant shows significant growth reduction after introduction into Escherichia coli strain SM101 bearing a defective LpxA gene (G189S), and under novobiocin supplementation 706784 2.3.1.129 H125A lower specific activity than wild-type 486258 2.3.1.129 H125N lower specific activity than wild-type 486258