Structural highlights
Function
[DN71_SULAC] Constrain negative DNA supercoils; may be involved in maintaining the integrity of their genome at high temperature.
Publication Abstract from PubMed
The proteins Sac7d and Sso7d belong to a class of small chromosomal proteins from the hyperthermophilic archaeon Sulfolobus acidocaldarius and S. solfactaricus, respectively. These proteins are extremely stable to heat, acid and chemical agents. Sac7d binds to DNA without any particular sequence preference and thereby increases its melting temperature by approximately 40 degrees C. We have now solved and refined the crystal structure of Sac7d in complex with two DNA sequences to high resolution. The structures are examples of a nonspecific DNA-binding protein bound to DNA, and reveal that Sac7d binds in the minor groove, causing a sharp kinking of the DNA helix that is more marked than that induced by any sequence-specific DNA-binding proteins. The kink results from the intercalation of specific hydrophobic side chains of Sac7d into the DNA structure, but without causing any significant distortion of the protein structure relative to the uncomplexed protein in solution.
The hyperthermophile chromosomal protein Sac7d sharply kinks DNA.,Robinson H, Gao YG, McCrary BS, Edmondson SP, Shriver JW, Wang AH Nature. 1998 Mar 12;392(6672):202-5. PMID:9515968[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Robinson H, Gao YG, McCrary BS, Edmondson SP, Shriver JW, Wang AH. The hyperthermophile chromosomal protein Sac7d sharply kinks DNA. Nature. 1998 Mar 12;392(6672):202-5. PMID:9515968 doi:10.1038/32455
