Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Recognition of GT mismatches by Vsr mismatch endonuclease
AU - Fox, Keith R.
AU - Allinson, Sarah L.
AU - Sahagun-Krause, Heidi
AU - Brown, Tom
PY - 2000/7/1
Y1 - 2000/7/1
N2 - The Vsr mismatch endonuclease recognises the sequence CTWGG (W = A or T) in which the underlined thymine is paired with guanine and nicks the DNA backbone on the 5'-side of the mispaired thymine. By using base analogues of G and T we have explored the functional groups on the mismatch pair which are recognised by the enzyme. Removal of the thymine 5-methyl group causes a 60% reduction in activity, while removing the 2-amino group of guanine reduces cleavage by 90%. Placing 5-aminopurine or nebularine opposite T generates mismatches which are cut at a much lower rate (0.1%). When either base is removed, generating a pseudoabasic site (1',2'-dideoxyribose), the enzyme still produces site-specific cleavage, but at only 1% of the original rate. Although TT and CT mismatches at this position are cleaved at a low rate (~ 1%), mismatches with other bases (such as GA and AC) and Watson-Crick base pairs are not cleaved by the enzyme. There is also no cleavage when the mismatched T is replaced with difluorotoluene.
AB - The Vsr mismatch endonuclease recognises the sequence CTWGG (W = A or T) in which the underlined thymine is paired with guanine and nicks the DNA backbone on the 5'-side of the mispaired thymine. By using base analogues of G and T we have explored the functional groups on the mismatch pair which are recognised by the enzyme. Removal of the thymine 5-methyl group causes a 60% reduction in activity, while removing the 2-amino group of guanine reduces cleavage by 90%. Placing 5-aminopurine or nebularine opposite T generates mismatches which are cut at a much lower rate (0.1%). When either base is removed, generating a pseudoabasic site (1',2'-dideoxyribose), the enzyme still produces site-specific cleavage, but at only 1% of the original rate. Although TT and CT mismatches at this position are cleaved at a low rate (~ 1%), mismatches with other bases (such as GA and AC) and Watson-Crick base pairs are not cleaved by the enzyme. There is also no cleavage when the mismatched T is replaced with difluorotoluene.
U2 - 10.1093/nar/28.13.2535
DO - 10.1093/nar/28.13.2535
M3 - Journal article
C2 - 10871403
AN - SCOPUS:0034234592
VL - 28
SP - 2535
EP - 2540
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 13
ER -