DNA-methyltransferase SsoII interaction with own promoter region binding site.

AUTOR(ES)

Shilov, I

RESUMO

The investigation of Sso II DNA-methyltransferase (M.Sso II) interaction with the intergenic region of Sso II restriction-modification system was carried out. Seven guanine residues protected by M. Sso II from methylation with dimethylsulfate and thus probably involved in enzyme-DNA recognition were identified. Six of them are located symmetrically within the 15 bp inverted repeat inside the Sso II promoter region. The crosslinking of Sso II methyltransferase with DNA duplexes containing 5-bromo-2'-deoxyuridine (br5dU) instead of thymidine was performed. The crosslinked products were obtained in all cases, thus proving that tested thymines were in proximity with enzyme. The ability to produce the crosslinked products in one case was 2-5-fold higher than in other ones. This allowed us to imply that thymine residue in this position of the inverted repeat could be in contact with M. Sso II. Based on the experimental data, two symmetrical 4 bp clusters (GGAC), which could be involved in the interaction with M. Sso II in the DNA-protein complex, were identified. The model of M. Sso II interaction with its own promoter region was proposed.

Documentos Relacionados

• Self-methylation of BspRI DNA-methyltransferase
• Specific binding of sso II DNA methyltransferase to its promoter region provides the regulation of sso II restriction-modification gene expression.
• In psychosis, cortical interneurons overexpress DNA-methyltransferase 1
• The interaction of DNA duplexes containing 2-aminopurine with restriction endonucleases EcoRII and SsoII.
• Changing the recognition specificity of a DNA-methyltransferase by in vitro evolution