2y7c

Atomic model of the Ocr-bound methylase complex from the Type I restriction-modification enzyme EcoKI (M2S1). Based on fitting into EM map 1534.Atomic model of the Ocr-bound methylase complex from the Type I restriction-modification enzyme EcoKI (M2S1). Based on fitting into EM map 1534.

2y7c, resolution 18.00Å Show:Asymmetric Unit Biological Assembly Structural highlights 2y7c is a 5 chain structure with sequence from Escherichia coli and Escherichia phage T7. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 18Å Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function T1SK_ECOLI Publication Abstract from PubMed Type-I DNA restriction-modification (R/M) systems are important agents in limiting the transmission of mobile genetic elements responsible for spreading bacterial resistance to antibiotics. EcoKI, a Type I R/M enzyme from Escherichia coli, acts by methylation- and sequence-specific recognition, leading to either methylation of DNA or translocation and cutting at a random site, often hundreds of base pairs away. Consisting of one specificity subunit, two modification subunits, and two DNA translocase/endonuclease subunits, EcoKI is inhibited by the T7 phage antirestriction protein ocr, a DNA mimic. We present a 3D density map generated by negative-stain electron microscopy and single particle analysis of the central core of the restriction complex, the M.EcoKI M(2)S(1) methyltransferase, bound to ocr. We also present complete atomic models of M.EcoKI in complex with ocr and its cognate DNA giving a clear picture of the overall clamp-like operation of the enzyme. The model is consistent with a large body of experimental data on EcoKI published over 40 years. The structure of M.EcoKI Type I DNA methyltransferase with a DNA mimic antirestriction protein.,Kennaway CK, Obarska-Kosinska A, White JH, Tuszynska I, Cooper LP, Bujnicki JM, Trinick J, Dryden DT Nucleic Acids Res. 2009 Feb;37(3):762-70. Epub 2008 Dec 11. PMID:19074193 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.