Single-protein Images Show How E. coli Repairs DNA While Replicating It
The success of E. coli bacteria depends on their ability to multiply very rapidly by dividing into new cells. The bacteria can divide as quickly as they can make an entire new copy of their DNA while minimizing errors. New work from researchers at the University of California, Davis College of Biological Sciences answers a key question about how E. coli fixes damage to DNA in the middle of duplicating it.
The machinery that duplicates E. coli DNA is called the replisome, said Tuan Pham, project scientist in the UC Davis Department of Microbiology and Molecular Genetics and first author on a paper describing the work published Sept. 23 in Proceedings of the National Academy of Sciences.
The replisome moves along the DNA strand, leaving two new strands behind it. But it when it encounters a damaged piece of DNA, such as a deleted base, it stalls and the cell activates a repair response, Pham said.
“The question is, how are lesions in the DNA repaired when encountered by the replisome?” said Stephen Kowalczykowski, distinguished professor of microbiology and molecular genetics at UC Davis and senior author on the paper.