Footprint analysis of the bsp RI DNA methyltransferase-DNA interaction.
The interaction between the GGCC-specific Bsp RI DNA methyltransferase (M. Bsp RI) and substrate DNA was studied with footprinting techniques using a DNA fragment that was unmodified on both strands. Footprinting with DNase I revealed an approximately 14 bp protected region. Footprinting with dimethylsulfate detected major groove interactions with the guanine bases of the recognition sequence. Reaction with 1,10-phenanthroline-copper did not show protection, suggesting that minor groove interactions play little role in sequence-specific recognition by M. Bsp RI. Hydroxyl radical footprinting revealed a protected stretch of 6 nt. The hydroxyl radical footprint of M. Bsp RI differs markedly from the the footprint reported for the Hha I and Sss I methyltransferases. The pattern of protection from dimethylsulfate and hydroxyl radicals suggests that the interactions of M. Bsp RI with DNA are similar to those detected in the co-crystal structure of the Hae III methyltransferase.
Finta
C
C
Institute of Biochemistry, Biological Research Center of the Hungarian Academy of Sciences, PO Box 521, Szeged 6701, Hungary.
Kiss
A
A
D003300:Copper; D004247:DNA / Q000378:metabolism*; D018983:DNA Footprinting; D015257:DNA-Cytosine Methylases / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D017665:Hydroxyl Radical; D009153:Mutagens / Q000494:pharmacology; D010618:Phenanthrolines / Q000494:pharmacology; D010957:Plasmids; D011480:Protease Inhibitors / Q000494:pharmacology; D013463:Sulfuric Acid Esters / Q000494:pharmacology
D009153:Mutagens; D010618:Phenanthrolines; D011480:Protease Inhibitors; D013463:Sulfuric Acid Esters; D017665:Hydroxyl Radical; D003300:Copper; D004247:DNA; D015257:DNA-Cytosine Methylases; C027823:Cytosine 5-methyltransferase; D003850:Deoxyribonuclease I; C007482:dimethyl sulfate; C025205:1,10-phenanthroline