Literature summary for 5.6.2.1 extracted from

Krogh, B.O.; Shuman, S.
Vaccinia topoisomerase mutants illuminate conformational changes during closure of the protein clamp and assembly of a functional active site (2001), J. Biol. Chem., 276, 36091-36099.

Protein Variants

Protein Variants	Comment	Organism
D298A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
E124A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
E299A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
F101A	mutant enzyme displayes an aberrant response to magnesium, rate of relaxation is lower by a factor of 4-5 in the presence of 5 mM magnesium than in its absence, the rate of relaxation in presence of NaCl plus magnesium is reduced by a factor of 10.20 compared to wild-type enzyme, affinity for 60-bp duplex is 8fold lower than that of wild-type enzyme	Vaccinia virus
F297A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
F88A	mutant enzyme displayes an aberrant response to magnesium, rate of relaxation is lower by a factor of 4-5 in the presence of 5 mM magnesium than in its absence, the rate of relaxation in presence of NaCl plus magnesium is reduced by a factor of 10-20 compared to wild-type enzyme, affinity for 60-bp duplex is 3fold lower than that of wild-type enzyme	Vaccinia virus
K104A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
K107A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
K108A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
K220A	supercoil relaxation by mutant enzyme in presence of NaCl and no divalent cation is slower by a factor of 5 than relaxation by wild-type enzyme, mutant enzyme is inhibited by including Mg2+ with NaCl, rate of relaxation in presence of NaCl plus Mg2+ is reduced by 20fold compared to wild-type enzyme	Vaccinia virus
K220H	supercoil relaxation by mutant enzyme in presence of NaCl and no divalent cation is slower by a factor of 5 than relaxation by wild-type enzyme, mutant enzyme is inhibited by including Mg2+ with NaCl, rate of relaxation in presence of NaCl plus Mg2+ is reduced by 40fold compared to wild-type enzyme	Vaccinia virus
K220Q	supercoil relaxation by mutant enzyme in presence of NaCl and no divalent cation is slower by a factor of 5 than relaxation by wild-type enzyme, mutant enzyme is inhibited by including Mg2+ with NaCl, rate of relaxation in presence of NaCl plus Mg2+ is reduced by 40fold compared to wild-type enzyme	Vaccinia virus
K220R	supercoil relaxation by mutant enzyme in presence of NaCl and no divalent cation is slower by a factor of 2 than relaxation by wild-type enzyme, neither stimulated nor inhibited by Mg2+, rate of relaxation in presence of NaCl plus Mg2+ is reduced by 8fold compared to wild-type enzyme	Vaccinia virus
N103A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
N228A	relaxation of supercoiled DNA in presence of NaCl and no divalent cation is slower by a factor of 8 than relaxation by the wild-type enzyme	Vaccinia virus
N228D	relaxation of supercoiled DNA in presence of NaCl and no divalent cation is slower by a factor of 40 than relaxation by the wild-type enzyme, mutant enzyme is inhibited by Mg2+, oligonucleotide cleavage is slower than that of wild-type enzyme by a factor of 200	Vaccinia virus
N228Q	relaxation of supercoiled DNA in presence of NaCl and no divalent cation is slower by a factor of 5 than relaxation by the wild-type enzyme, not stimulated by including magnesium with NaCl	Vaccinia virus
N228S	relaxation of supercoiled DNA in presence of NaCl and no divalent cation is slower by a factor of 2 than relaxation by the wild-type enzyme	Vaccinia virus
N99A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
Q116A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
R90A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
R97A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus
S204A	mutant protein relaxes supercoiled DNA slowly and is strongly inhibited in the presence of salt plus magnesium, the rate of single-turnover religation by covalently bound S204N is indistinguishable from wild-type within the limits of the assay	Vaccinia virus
T296A	relaxation rate is equivalent to that of the wild-type enzyme in absence and presence of Mg2+	Vaccinia virus

Organism

Organism	UniProt	Comment	Textmining
Vaccinia virus	-	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
negatively supercoiled DNA	-	Vaccinia virus	?	-	?