3 - 5 minutes
||Bacteria Escherichia coli
||Hammar P et al. The lac repressor displays facilitated diffusion in living cells. Science. 2012 June 22 336(6088):1595-1598. doi:10.1126/science.1221648 p.1596 left column top paragraphPubMed ID22723426
||P.1596 caption to figure 1B: "The association rate to a single chromosomal operator is determined by studying the rebinding kinetics of the repressor to the operator after removing the inducer."
||P.1595 right column bottom paragraph: "When [investigators] measured the association rate in the strain with a single lacOsym (JE101), [they] found that it took an average time of 56 ± 2 s (SEM) for any of the three to five fully active (supplementary text) LacI-Venus dimers to bind the operator site (Fig. 1B). This implies that the time required for a single repressor molecule to bind lacOsym is 3 to 5 min. These observations are in excellent agreement with recent theoretical binding-time predictions (3.5 min) based on facilitated diffusion by sliding (ref 13) (supplementary text). This overall agreement suggests the possibility of a sliding mechanism, without proving any of the specific assumptions made in the theoretical model."