Biochemical characterization of Escherichia coli DNA helicase I.
The gene product of F tral is a bifunctional protein which nicks and unwinds the F plasmid during conjugal DNA transfer. Further biochemical characterization of the Tral protein reveals that it has a second, much lower, Km for ATP hydrolysis, in addition to that previously identified. Measurement of the single-stranded DNA-stimulated ATPase rate indicates that there is co-operative interaction between the enzyme monomers for maximal activity. Furthermore, 18O-exchange experiments indicate that Tral protein hydrolyses ATP with, at most, a low-level reversal of the hydrolytic step during each turnover.
Dash
P K
PK
Department of Biological Sciences, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213.
Traxler
B A
BA
Panicker
M M
MM
Hackney
D D
DD
Minkley
E G
EG
D000251:Adenosine Triphosphatases / Q000378:metabolism; D003227:Conjugation, Genetic; D004265:DNA Helicases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D005144:F Factor; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism; D013347:Subcellular Fractions
D029968:Escherichia coli Proteins; D000251:Adenosine Triphosphatases; C027093:TraI protein, E coli; D004265:DNA Helicases; D010100:Oxygen