Download MendeleyIntron-encoded homing endonuclease I-TevI also functions as a transcriptional autorepressor.
Edgell, D.R., Derbyshire, V., Van Roey, P., LaBonne, S., Stanger, M.J., Li, Z., Boyd, T.M., Shub, D.A., Belfort, M.(2004) Nat Struct Mol Biol 11: 936-944
- PubMed: 15361856 Search on PubMed
- DOI: https://doi.org/10.1038/nsmb823
- Primary Citation Related Structures:
1T2T - PubMed Abstract:
Customary binding sites of intron-encoded homing endonucleases lie within cognate intronless alleles, at the so-called homing sites. Here, we describe a novel, high-affinity binding site for I-TevI endonuclease, encoded within the group I td intron of phage T4. This site is an operator that overlaps the T4 late promoter, which drives I-TevI expression from within the td intron. I-TevI binds the operator and homing sites with equal affinity, and functions as a transcriptional autorepressor. Distinct sequence and spacing requirements of the catalytic domain result in reduced cleavage activity on operator DNA. Crystallographic studies showed that the overall interactions of the DNA-binding domain with the operator and homing sites are similar, but have some different hydrogen-bonding contacts. We present a model in which the flexibility in protein-DNA interactions allows I-TevI to bind variant intronless alleles to promote intron mobility while facilitating its function in autorepression, and thereby persistence in its host.
- Wadsworth Center, New York State Department of Health, Center for Medical Sciences, 150 New Scotland Avenue, Albany, New York 12208, USA.
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