20.500.12556/RUL-128248 The Escherichia coli colibactin resistance protein ClbS is a novel DNA binding protein that protects DNA from nucleolytic degradation Cells employ specific and nonspecific mechanisms to protect their genome integrity against exogenous and endogenous factors. The clbS gene is part of the polyketide synthase machinery (pks genomic island) encoding colibactin, a genotoxin implicated in promoting colorectal cancer. The pks is found among the Enterobacteriaceae, in particular Escherichia coli strains of the B2 phylogenetic group. Several resistance mechanisms protect toxin producers against toxicity of their products. ClbS, a cyclopropane hydrolase, was shown to confer colibactin resistance by opening its electrophilic cyclopropane ring. Here we report that ClbS sustained viability and enabled growth also of E. coli expressing another genotoxin, the Usp nuclease. The recA::gfp reporter system showed that ClbS protects against Usp induced DNA damage. To elucidate the mechanism of ClbS mediated protection, we studied the DNA binding ability of the ClbS protein. We show that ClbS directly interacts with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), whereas ssDNA seems to be the preferred substrate. Thus, the ClbS DNA-binding characteristics may serve bacteria to protect their genomes against DNA degradation. ClbS DNA-binding protein DNA damage protection pks genomic island Escherichia coli true false true Angleški jezik Ni določen Članek v reviji 2021-07-07 10:20:48 2021-07-07 10:20:48 2022-09-07 04:13:57 0000-00-00 00:00:00 2019 0 0 Str. 50-54 Vol. 79 2019 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579 1568-7856 10.1016/j.dnarep.2019.05.003 5079119 RAZ_Molan_Katja_2019.pdf RAZ_Molan_Katja_2019.pdf 1 57EC29A84460543A44B05975D5E4F225 5b3d7e860be39ca5e7337a0adc65f7157388c1b856e3933e4b850f9a548c4737 891358a6-defc-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144919 https://www.sciencedirect.com/science/article/pii/S1568786418303021 0 19bc9b27-defc-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144918 Biotehniška fakulteta 0 0 0