| 摘要 |
Compositions are disclosed comprising a high fidelity SpeI restriction endonuclease enzyme having an artificially introduced amino acid mutation corresponding to position E59, P65, S108, N172, K174, Q179, G182, or Y55 in SpeI (SEQ ID No. 17). The SpeI mutation may be E59A, P65A, S108A, N172A, K174A, Q179A, G182A, or Y55F. Also claimed are methods of identifying a fidelity index (FI) of the aforementioned SpeI restriction enzyme variants, wherein the methods comprise selecting a reaction buffer and DNA substrate with a binding site for SpeI, permitting serially diluted SpeI variants to cleave the DNA substrate, and determining the FI for the SpeI variant. |
