spacer
View the latest EBI news stories and important announcements...
more

spacer
Search The CSA
PDB ID
UNIPROT ID
EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 2adm

E.C. namesite-specific DNA-methyltransferase (adenine-specific)
SpeciesThermus aquaticus (Bacteria)
E.C. Number (IntEnz) 2.1.1.72
CSA Homologues of 2admThere are 12 Homologs
CSA Entries With UniProtID P14385
CSA Entries With EC Number 2.1.1.72
PDBe Entry 2adm
PDBSum Entry 2adm
MACiE Entry M0046

Literature Report

IntroductionN-6 adenine-specific DNA-methyltransferases catalyse the transfer of a methyl group from S-adenosyl-L-methionine to either the exocyclic N-6 of an adenine or to N-4 of a cytosine contained in a specific DNA recognition sequence. Methylation protects the DNA from restriction from host endonucleases.
MechansimThe binding site for S-adenosyl-L-methionine is located in a cavity in the N-terminal domain. Its positive charge is compensated for by seven negatively charged residues, Glu22, Glu45, Glu71, Glu78, Glu84, Asp89 and Glu113. Hydrogen bonds occur with Asp89, Phe90, Glu71, Glu45, Glu22 and Thr23 in addition to many hydrophobic interactions. The DNA binds in the cleft formed by the N- and C-terminal domains which has a high positive electrostatic potential allowing interaction with the negative DNA phosphate backbone. The adenine to be methylated is brought to the active CH3 group in S-adenosyl-L-methionine by looping out of the base into a gap between the flexible N-terminal loop and beta strand.
Reaction

Catalytic Sites for 2adm

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ProA106106macie:mainChainAmide
AsnA105105macie:sideChain
TyrA108108macie:sideChain

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ProB106106macie:mainChainAmide
AsnB105105macie:sideChain
TyrB108108macie:sideChain

Literature References

Notes:
Schluckebier G
A model for DNA binding and enzyme action derived from crystallographic studies of the TaqI N6-adenine-methyltransferase.
Gene 1995 157 131-134
PubMed: 7607476
Pues H
Functional roles of the conserved aromatic amino acid residues at position 108 (motif IV) and position 196 (motif VIII) in base flipping and catalysis by the N6-adenine DNA methyltransferase from Thermus aquaticus.
Biochemistry 1999 38 1426-1434
PubMed: 9931007
spacer
spacer