EcoRI variant N199H has enhanced specific activity.
The Asn199 residue of the EcoRI restriction endonuclease has been replaced with other amino acids to investigate whether it mediates nucleotide recognition or catalytic activity. Cassette mutagenesis gave variants of EcoRI: N199D, N199H, N199L, N199R, N199S and N199V. Their relative cleavage rates were found to be in the following order: N199H > EcoRI (wild type; wt) > N199L > N199V > N199S > N199R > N199D. In particular, EcoRI variant N199H showed about a twofold higher specific activity than that of the wt enzyme.
Kim
J J
JJ
Korea Research Institute of Biotechnology and Bioscience, K.I.S.T., Yusong, Taejon, South Korea.
Min
K T
KT
Kim
M H
MH
Augh
S J
SJ
Kim
B D
BD
Lee
D S
DS
D001216:Asparagine / Q000502:physiology*; D001483:Base Sequence; D004279:DNA, Viral / Q000378:metabolism; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry / Q000378:metabolism*; D006639:Histidine / Q000502:physiology*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010957:Plasmids / Q000378:metabolism
D004279:DNA, Viral; D006639:Histidine; D001216:Asparagine; D015246:Deoxyribonuclease EcoRI