- O'Brien E, Holt ME, Thompson MK, Salay LE, Ehlinger AC, Chazin WJ, Barton JK. Response to Comments on "The [4Fe4S] cluster of human DNA primase functions as a redox switch using DNA charge transport". Science (New York, N.Y.). 2017 Jul 21;357(6348). PMID: 28729485 [PubMed].
Baranovskiy et al and Pellegrini argue that, based on structural data, the path for charge transfer through the [4Fe4S] domain of primase is not feasible. Our manuscript presents electrochemical data directly showing charge transport through DNA to the [4Fe4S] cluster of a primase p58C construct and a reversible switch in the DNA-bound signal with oxidation/reduction, which is inhibited by mutation of three tyrosine residues. Although the dispositions of tyrosines differ in different constructs, all are within range for microsecond electron transfer.