Single-molecule studies of repressor-DNA interactions show long-range interactions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 15994229.
- Also identified by PMC identifier 1168954.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
We have performed single-molecule studies of GFP-LacI repressor proteins bound to bacteriophage lambda DNA containing a 256 tandem lac operator insertion confined in nanochannels. An integrated photon molecular counting method was developed to determine the number of proteins bound to DNA. By using this method, we determined the saturated mean occupancy of the 256 tandem lac operators to be 13, which constitutes only 2.5% of the available sites. This low occupancy level suggests that the repressors influence each other even when they are widely separated, at distances on the order of 200 nm, or several DNA persistence lengths.
Medical subject headings
- Bacteriophage lambda
- DNA, Viral
- DNA-Binding Proteins
- Operator Regions, Genetic
- Repressor Proteins