1eg2

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spinqualitylabelsall models 1eg2, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF RHODOBACTER SPHEROIDES (N6 ADENOSINE) METHYLTRANSFERASE (M.RSRI)

Overview

DNA methylation is important in cellular, developmental and disease, processes, as well as in bacterial restriction-modification systems., Methylation of DNA at the amino groups of cytosine and adenine is a common, mode of protection against restriction endonucleases afforded by the, bacterial methyltransferases. The first structure of an N:6-adenine, methyltransferase belonging to the beta class of bacterial, methyltransferases is described here. The structure of M. RSR:I from, Rhodobacter sphaeroides, which methylates the second adenine of the GAATTC, sequence, was determined to 1.75 A resolution using X-ray crystallography., Like other methyltransferases, the enzyme contains the methylase fold and, has well-defined substrate binding pockets. The catalytic core most, closely resembles the PVU:II methyltransferase, a cytosine amino, methyltransferase of the same beta group. The larger nucleotide binding, pocket observed in M. RSR:I is expected because it methylates adenine., However, the most striking difference between the RSR:I methyltransferase, and the other bacterial enzymes is the structure of the putative DNA, target recognition domain, which is formed in part by two helices on an, extended arm of the protein on the face of the enzyme opposite the active, site. This observation suggests that a dramatic conformational change or, oligomerization may take place during DNA binding and methylation.

About this Structure

1EG2 is a Single protein structure of sequence from Rhodobacter sphaeroides with MTA as ligand. Active as Site-specific DNA-methyltransferase (adenine-specific), with EC number 2.1.1.72 Full crystallographic information is available from OCA.

Reference

Structure of RsrI methyltransferase, a member of the N6-adenine beta class of DNA methyltransferases., Scavetta RD, Thomas CB, Walsh MA, Szegedi S, Joachimiak A, Gumport RI, Churchill ME, Nucleic Acids Res. 2000 Oct 15;28(20):3950-61. PMID:11024175

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