1SFE

ADA O6-METHYLGUANINE-DNA METHYLTRANSFERASE FROM ESCHERICHIA COLI

Summary for 1SFE

• Entry DOI: 10.2210/pdb1sfe/pdb
• Descriptor: ADA O6-METHYLGUANINE-DNA METHYLTRANSFERASE (2 entities in total)
• Functional Keywords: enzyme, transferase, methyltransferase, nucleic acid binding protein, dna repair protein, dna-binding protein, dna binding protein
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 19766.59

Authors

Moore, M.H.,Gulbis, J.M.,Dodson, E.J.,Demple, B.,Moody, P.C.E. (deposition date: 1996-06-21, release date: 1996-12-23, Last modification date: 2024-02-14)

Primary citation

Moore, M.H.,Gulbis, J.M.,Dodson, E.J.,Demple, B.,Moody, P.C.
Crystal structure of a suicidal DNA repair protein: the Ada O6-methylguanine-DNA methyltransferase from E. coli.
EMBO J., 13:1495-1501, 1994

PubMed Abstract: The mutagenic and carcinogenic effects of simple alkylating agents are mainly due to methylation at the O6 position of guanine in DNA. O6-methylguanine directs the incorporation of either thymine or cytosine without blocking DNA replication, resulting in GC to AT transition mutations. In prokaryotic and eukaryotic cells antimutagenic repair is effected by direct reversal of this DNA damage. A suicidal methyltransferase repair protein removes the methyl group from DNA to one of its own cysteine residues. The resulting self-methylation of the active site cysteine renders the protein inactive. Here we report the X-ray structure of the 19 kDa C-terminal domain of the Escherichia coli ada gene product, the prototype of these suicidal methyltransferases. In the crystal structure the active site cysteine is buried. We propose a model for the significant conformational change that the protein must undergo in order to bind DNA and effect methyl transfer.

PubMed: 8156986

Experimental method

X-RAY DIFFRACTION (2.1 Å)