Crystal structure of Type I restriction enzyme EcoKI M protein (EC 2.1.1.72) (M.EcoKI)Crystal structure of Type I restriction enzyme EcoKI M protein (EC 2.1.1.72) (M.EcoKI)
Structural highlights
2ar0 is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
T1MK_ECOLI The M and S subunits together form a methyltransferase (MTase) that methylates two adenine residues in complementary strands of a bipartite DNA recognition sequence. In the presence of the R subunit the complex can also act as an endonuclease, binding to the same target sequence but cutting the DNA some distance from this site. Whether the DNA is cut or modified depends on the methylation state of the target sequence. When the target site is unmodified, the DNA is cut. When the target site is hemimethylated, the complex acts as a maintenance MTase modifying the DNA so that both strands become methylated. The EcoKI enzyme recognizes 5'-AACN(6)GTGC-3'.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
