Crystal Structure of Human DNA Methyltransferase 1

Crystal structure of human L-isoaspartyl methyltransferase.

The enzyme l-isoaspartyl methyltransferase initiates the repair of damaged proteins by recognizing and methylating isomerized and racemized aspartyl residues in aging proteins. The crystal structure of the human enzyme containing a bound S-adenosyl-l-homocysteine cofactor is reported here at a resolution of 2.1 A. A comparison of the human enzyme to homologs from two other species reveals sever...

Crystal structure of MboIIA methyltransferase.

DNA methyltransferases (MTases) are sequence-specific enzymes which transfer a methyl group from S-adenosyl-L-methionine (AdoMet) to the amino group of either cytosine or adenine within a recognized DNA sequence. Methylation of a base in a specific DNA sequence protects DNA from nucleolytic cleavage by restriction enzymes recognizing the same DNA sequence. We have determined at 1.74 A resolutio...

Studies of Mechanisms Controlling Dna Methyltransferase 1 Studies of Mechanisms Controlling Dna Methyltransferase 1

We present a simple, non-radioactive assay for DNA methyltransferase activity and DNA binding. As most proteins are studied as GFP fusions in living cells, we used a GFP binding nanobody coupled to agarose beads (GFP nanotrap) for rapid one-step purification. Immobilized GFP fusion proteins were subsequently incubated with different fluorescently labeled DNA substrates. The absolute amounts and...

DNA ( cytosine - 5 ) - methyltransferase 1 - [ Isoform 1 ]

The murine equivalent of the human DNMT1 (DNA [cytosine-5]-methyltransferase 1; Swiss-Prot accession number: P26358) gene was deleted in ES cells via gene targeting [1]. Dnmt1-/cells possessed dramatically decreased genomic methylation and were viable; however, the mutation caused a homozygous lethal phenotype when introduced into the germline (see Table of experimental models for DNMT1) [1]. C...

DNMT 1 ( DNA ( cytosine - 5 - ) - methyltransferase 1 ) )