INTENSIFICATION OF DNA-REPAIR PROCESSES BY PARA-AMINOBENZOIC ACID IN ESCHERICHIA-COLI K-12

  • 1 January 1982
    • journal article
    • research article
    • Vol. 18  (3) , 381-391
Abstract
Studies of the role of the physiologically active natural compound p-aminobenzoic acid (PABA) in genetic processes showed that PABA interacts with bacterial DNA and strongly increases the effectiveness of repair processes under the mutagenic actions of NMU (nitrosomethylurea), NEU (nitrosoethylurea), MMS (methyl methanesulfonate) and EMS (ethyl methanesulfonate). These properties of PABA depended on the activity of enzymatic systems of DNA repair and were most pronounced in repair-proficient strains of E. coli. The cooperative action on both NMU and PABA on wild type E. coli led to enhanced viability (13-100 times higher) and decreased the rate of induced reversions (5-60 times lower), in comparison with mutagenic action of pure NMU. The specific function of PABA was called reparagenic and PABA itself was called a reparagen. UV splectroscopy and NMR were used to show that PABA does not interact with MMS and NMU in vitro and does not change the rate of hydrolysis of the mutagens. Used in a wide range of concentrations, PABA did not induce mutations in bacterial cells and did not increase the rate of genetic recombination. The discovery of the role of PABA in repair processes opens up the possibility of examining the interaction between DNA in a complex with reparagen. Also, the dominant and recessive genes of the repair process can be further studied using PABA.