Conversion of the Tetrameric Restriction Endonuclease Bse634I into a Dimer: Oligomeric Structure–Stability–Function Correlations

Evolution of Quaternary Structure in a Homotetrameric Enzyme

“…11,[25][26][27][28] The exercise is not a trivial one, since the change in oligomeric state often results in exposure of previously buried hydrophobic surfaces and, consequently, problems of aggregation and solubilisation. However, in the case of E. coli DHDPS, generation of obligate dimeric structures proved feasible, since the dimer-dimer interface is small and the centre of the tetramer contains a large, water-filled channel.…”

Fidelity of DNA Sequence Recognition by the SfiI Restriction Endonuclease Is Determined by Communications between Its Two DNA-Binding Sites

“…16 Cognate termini could also activate another tetrameric restriction enzyme, Bse634I, to cut its recognition site. 17 The first Type II restriction enzyme found to be a tetramer that acts concurrently at two DNA sites was the SfiI endonuclease. 18 SfiI recognises an interrupted 8 bp palindrome, GGCCNNNN↓NGGCC (where ↓ marks the point of cleavage and N is any base 19 ) but has low activity when bound to a single site.…”

Extra Copper‐mediated Enhancement of the DNA Cleavage Activity Supported with Wild‐type Cu, Zn Superoxide Dismutase

“…25 In these experiments, the apparent rate constants (k 1 ) of formation of the nicked form from the supercoiled DNA were measured against the single concentration of DNA substrate and holo SOD. Cleavage kinetics of 9.8 μmol/L pBR322 DNA with 1.4 μmol/L holo SOD was recorded in 20 mmol/L Tris-HCl buffer (pH 7.4) containing 0-8 equivalents of CuSO 4 at 37 ℃.…”