Before revision:  , and consider various abundances of cognate and non-cognate TFs to assess the influence of competitor molecules thatalso move along the DNA . We show that molecular crowding on the DNA always leads to longer times required by TF molecules to locate their target sites as well as to lower occupancy, which may confer a general mechanism to control gene activity levels globally  .
After revision:  , and consider various abundances of cognate and non-cognate TFs . We show that, for both obstacles that move on the DNA and obstacles that are fixed on the DNA, changes in search time are not statistically significant in case of biologically relevant crowding levels on the DNA. In the case of non-cognate proteins that slide on the DNA, molecular crowding on the DNA always leads to longer times required by TF molecules to locate their target sites as well as to lower occupancy, which may confer a general mechanism to control gene activity levels globally .