Flap Endonuclease Activity of Gene 6 Exonuclease of Bacteriophage T7

Mitsunobu, Hitoshi; Zhu, Bin; Lee, Seung-Joo; Tabor, Stanley; Richardson, Charles C.

doi:10.1074/jbc.m113.538611

Cited by 17 publications

(25 citation statements)

References 68 publications

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“…In particular, the predicted structure of gp6 is very similar to the known structure of T5 exonuclease, which also has flap endonuclease activity 13 . Interestingly, the endonuclease activities of gp6 and T5 exonuclease are dependent on the length of the 5′-flap; the longer the length of the 5′-flap, the lower the flap endonuclease activity 5 , 14 . Such dependency is not observed in eukaryote FEN proteins.…”

Section: Flap Endonuclease Activity Of Gp6mentioning

confidence: 63%

“…However, gp2.5 can overcome this inhibition since it stimulates both activities of gp6. When gp6 is incubated with a 500-bp duplex DNA, the exonuclease activity is 3.5-fold more active in the presence of gp2.5 than in its absence 5 . This stimulation does not occur when E. coli single-strand binding protein is substituted for gp2.5.…”

Section: Degradation Of Host Dnamentioning

confidence: 97%

“…gp6 has flap endonuclease activity as well as 5′ to 3′ exonuclease activity 5 . The flap endonuclease activity is considerably weaker than the exonuclease activity: the rate of hydrolysis of blunt-ended substrates ranges from 10- to 120-fold faster than that found with substrates having a 5′-overhang 5 .…”

Section: Flap Endonuclease Activity Of Gp6mentioning

confidence: 99%

“…The exonuclease activity has been studied extensively and has been shown to initiate hydrolysis at the 5′-termini of duplex DNA, hydrolyzing the DNA in a non-processive manner to release nucleoside 5′-monophosphates 1 , 2 . We recently found that gp6 also has a structure-specific 5′-flap endonuclease activity 5 . The endonuclease activity depends on the length of 5′-flaps: the activity decreases as the length increases.…”

Section: Introductionmentioning

confidence: 99%

“…We recently characterized the flap endonuclease activity of gp6 5 . The major position of cleavage occurs one nucleotide into the duplex region adjacent to double-stranded/single-stranded DNA junction.…”

Section: Introductionmentioning

confidence: 99%

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Flap endonuclease of bacteriophage T7

Mitsunobu¹,

Zhu

Lee³

et al. 2014

Bacteriophage

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Gene 6 protein of bacteriophage T7 has 5′-3′-exonuclease activity specific for duplex DNA. We have found that gene 6 protein also has flap endonuclease activity. The flap endonuclease activity is considerably weaker than the exonuclease activity. Unlike the human homolog of gene 6 protein, the flap endonuclease activity of gene 6 protein is dependent on the length of the 5′-flap. This dependency of activity on the length of the 5′-flap may result from the structured helical gateway region of gene 6 protein which differs from that of human flap endonuclease 1. The flap endonuclease activity provides a mechanism by which RNA-terminated Okazaki fragments, displaced by the lagging strand DNA polymerase, are processed. 3′-extensions generated during degradation of duplex DNA by the exonuclease activity of gene 6 protein are inhibitory to further degradation of the 5′-terminus by the exonuclease activity of gene 6 protein. The single-stranded DNA binding protein of T7 overcomes this inhibition.

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Section: Flap Endonuclease Activity Of Gp6mentioning

confidence: 63%

Section: Degradation Of Host Dnamentioning

confidence: 97%