beta-Lactamase of Lysobacter enzymogenes: cloning, characterization and expression of the gene and comparison of the enzyme to other lactamases
1993
Boras, G.J. | Au, S. | Roy, K.L. | Von Tigerstrom, R.G.
The gene for the periplasmic beta-lactamase of Lysobacter enzymogenes was isolated as part of a 1017 bp EcoRI fragment and the nucleotide sequence of the gene was determined. It has a G + C content of 71.5% and encodes a 27 amino acid signal sequence and the mature beta-lactamase of 276 amino acids which has a mass of 29146 Da. The enzyme appears to be unique to L. enzymogenes but its amino acid sequence shows a high degree of homology with the amino acid sequences of the lactamase from Citrobacter diversus and other Class A beta-lactamases. The beta-lactamase gene of L. enzymogenes was expressed in Escherichia coli using pUC118 as the vector. The production of active beta-lactamase was highest after the active growth phase of the expression host and reached levels which were about three times higher than those obtained with L. enzymogenes.
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