Sandbox 666: Difference between revisions
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== Structure == | == Structure == | ||
EcoRI is a homodimer, so it has two identical subunits ( | EcoRI is a homodimer, so it has two identical subunits () of 31 kDa, but it possible to have homotetramers at high concentrations.. The constitutive monomers are 276 amino acids long. EcoRI and all the other restriction enzymes show a common structural core which is a α/β domain. The constitutive subunits of EcoRI are organized into a single α/β domain (five stranded β sheet which are surrounded on by α helices). Four of these five β strands are parallel whereas the fourth (β4) is in an anti-parallel orientation to the others. | ||
The N-terminal section of each subunit forms, with a β-hairpin, an “arm” which wraps around the DNA molecule. (The arm brings the DNA molecule to the catalytic cleft.) | The N-terminal section of each subunit forms, with a β-hairpin, an “arm” which wraps around the DNA molecule. (The arm brings the DNA molecule to the catalytic cleft.) | ||
