منابع مشابه
Processivity of DNA exonucleases.
A homopolymer system has been developed to examine the digestion strategies of DNA exonucleases. Escherichia coli exonuclease I and lambda-exonuclease, are processive enzymes. However, T7 exonuclease, spleen exonuclease, E. coli exonuclease III, the 3' leads to 5'-exonuclease of T4 DNA polymerase, and both the 3' leads to 5' and the 5' leads to 3' activity of E. coli DNA polymerase I dissociate...
متن کاملA peptide switch regulates DNA polymerase processivity.
Chromosomal DNA polymerases are tethered to DNA by a circular sliding clamp for high processivity. However, lagging strand synthesis requires the polymerase to rapidly dissociate on finishing each Okazaki fragment. The Escherichia coli replicase contains a subunit (tau) that promotes separation of polymerase from its clamp on finishing DNA segments. This report reveals the mechanism of this pro...
متن کاملDNA Replication: A familiar ring to DNA polymerase processivity
Structural similarity reveals that prokaryotic and eukaryotic DNA polymerases share a mechanism for processivity--but the conservation of additional chromosomal replication mechanisms remains to be determined.
متن کامل5 ’ + 3 ’ - Exonucleases of Bacteriophage
Two enzyme activities which release nucleotides preferentially from the 5’ termini of DNA were found in T4-infected Escherichia coli. Since no corresponding activities were found in uninfected cells, the activities appear to be induced by T4. Both activities are capable of excising pyrimidine dimers from ultraviolet-irradiated DNA which has been treated with T4 endonuclease V. One of the activi...
متن کاملThe dynamic processivity of the T4 DNA polymerase during replication.
The polymerase (gp43) processivity during T4 replisome mediated DNA replication has been investigated. The size of the Okazaki fragments remains constant over a wide range of polymerase concentrations. A dissociation rate constant of approximately 0.0013 sec(-1) was measured for the polymerases from both strands, consistent with highly processive replication on both the leading and lagging stra...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1978
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)38226-1