МУТАЦИИ В ГЕНЕ FUSA, КОДИРУЮЩЕМ ФАКТОР ЭЛОНГАЦИИ G У КОРИНЕФОРМНЫХ БАКТЕРИЙ, ПРИВОДЯТ К ПОВЫШЕНИЮ ПРОДУКЦИИ ЛИЗИНА

Abstract

Resistance to fusidic acid in Corynebacterium glutamicum and Brevibacterium flavum is associated with mutations in the fusA gene that encodes the elongation factor G (EF-G). From 2% to 10% of fusidic acid-resistant clones were shown to produce more lysine than parent strains. Sequencing of the fusA gene in clones with high level of lysine production permitted to find out two mutations in the gene at position 1383 - d383G and С1383А. These mutations cause the amino acid replacement at position 461 in the protein EF-G, namely, histidine is substituted by glutamine (H461Q). The mutation d383G was introduced in the chromosomal copy of the fusA gene in C. glutamicum and B. flavum strains by homologous recombination. All clones containing the mutant variant of the fusA gene produced 10% more lysine than the parent strains.