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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It was shown that bacteriophage tf as well as bacteriophages phi p4/40, phi p25/42, phi p23/40 and phi p6/40, which are specific to different P. putida strains, contain the single strand breaks in their DNA. The breaks are localized in one strand of DNA molecules and are repairable with T4 DNA ligase. Bacteriophage tf has no detectable DNA homology with phi p4/40, phi p25/42, phi p23/40 and phi p6/40 bacteriophages. All the phages studied have no relation with other known Pseudomonas phages. Bacteriophages phi p4/40 and phi p25/42 share the extensive DNA homology.
Mol Gen Mikrobiol Virusol 1988 May
PMID:[Bacteriophages of Pseudomonas putida containing single-stranded canonical DNA breaks]. 313 62

Structural defects, affecting T4 DNA ligase function, were revealed with the help of synthetic DNA duplexes, containing modifications at single nick. Changes of configuration at C2' and C3' atoms of furanose in the acceptor terminus lead to total blocking of the nick sealing activity of T4 DNA ligase. On the contrary, substitution of 3'-terminal deoxyribonucleotide for ribonucleotide doesn't affect the enzyme's action. The duplex looses all of it's substrate activity if the next from the nick G.C pair is substituted for the noncomplementary G.C pair. In DNA duplexes containing an unpaired base in the nick, elimination of the extrahelical nucleotide proceeds the ligation step. In these cases the duplex substrate activity decreases depending on the extent of extrahelical base stacking into the double stranded DNA.
Mol Biol (Mosk)
PMID:[T4-DNA ligase: substrate properties of synthetic DNA-duplexes with structural anomalies]. 318 24

The enzymatic ligation of 5-10-membered synthetic oligodeoxyribonucleotides forming the complementary DNA-like duplexes has been studied. The possibility of selective DNA ligase catalyzed ligation of 5'-adenylylated derivatives of oligonucleotides in the absence of rATP and also the selective joining of cohesive ends in the presence of blunt ends in the complex mixtures of oligonucleotides at definite concentrations of rATP have been demonstrated. The influence of length and sequence of short synthetic DNA-duplexes on the efficiency of ligation has been shown. We have identified the unusual octanucleotide dpTATAATAT, that being able to form concatemer complexes could not be polymerized by T4 DNA ligase.
Mol Biol (Mosk)
PMID:[Controlled ligation of oligodeoxyribonucleotides of DNA-ligase of the T4 phage]. 325 53

A DNA sequence has been isolated from Schizosaccharomyces pombe which promotes high frequency transformation of plasmids in the same organism. It is closely linked to the DNA ligase gene CDC17 and has therefore been named ARS17 although in structure it differs substantially from ARS elements in Saccharomyces cerevisiae. ARS17 spans some 1.8 kb of DNA and deletion of any part of this region affects activity. Moreover, there does not appear to be any short sequence which is, by itself, sufficient for high frequency transformation. ARS17 lies between and partly overlaps two divergently transcribed genes and it is extremely AT rich. It lacks the consensus sequence found in S. cerevisiae ARSs and it has no ARS activity in S. cerevisiae.
Mol Gen Genet 1987 Apr
PMID:Characterisation of an autonomously replicating sequence from the fission yeast Schizosaccharomyces pombe. 329

We have investigated the fate of the yeast 2 micron DNA plasmid in strains with a temperature sensitive mutation of DNA ligase. At the restrictive temperature the plasmid DNA collects as an open circular form with single strand interruptions. Both alpha factor pheromone, which arrests cells before the start of S phase, and hydroxyurea, which blocks progression through S phase, prevent the appearance of the open circular form. Thus, interrupted plasmid DNA does not accumulate in the absence of DNA replication. On average the interrupted molecules contain four to five interruptions per newly replicated strand. Most of the interruptions are nicks (breaks in a single phosphate ester bond) rather than gaps (absence of one or more nucleotides in a strand) as judged by the in vitro conversion of the interrupted molecules into a covalently closed form by DNA ligase. Mapping of the position of the interruptions reveals no predominate sites.
Mol Gen Genet 1986 Jun
PMID:Accumulation of single strand interruptions within the yeast 2 microns DNA plasmid during replication in a DNA ligase mutant. 352 47

We have cloned CDC9, the structural gene for Saccharomyces cerevisiae DNA ligase, and investigated its transcriptional regulation both as a function of cell cycle stage and after UV irradiation. The steady-state level of DNA ligase mRNA increases at least fourfold in late G1, after the completion of start but before S phase. This high level of CDC9 mRNA then decays with an apparent half-life of ca. 20 min and remains at a low basal level throughout the rest of the cell cycle. The accumulation of CDC9 mRNA in late G1 is dependent upon the completion of start but not the CDC7 and CDC8 functions. Exposure of cells to UV light elicits an eightfold increase in DNA ligase mRNA levels.
Mol Cell Biol 1985 Jan
PMID:Regulation of CDC9, the Saccharomyces cerevisiae gene that encodes DNA ligase. 388 10

A sensitive and quantitative assay for DNA ligase has been developed which is suitable for the analysis of crude cell extracts of yeast. The assay is sufficiently sensitive to detect the low levels of DNA ligase activity remaining in cdc9 mutants of Saccharomyces cerevisiae. Indeed, we have been able to show that this residual activity is temperature-sensitive, thus establishing finally that CDC9 is the structural gene for DNA ligase.
Mol Gen Genet 1985
PMID:An improved assay for DNA ligase reveals temperature-sensitive activity in cdc9 mutants of Saccharomyces cerevisiae. 390 Jun 39

The mechanism of activating action of ATP on the repair synthesis of DNA was studied in the chromatin isolated from rat liver (G0). It was shown that chromatin catalyzed the conversion dNTP leads to dNDP leads to dNMP leads to NdR. The principal mechanism of activating action of ATP is the maintenance of dNTP levels. The maintenance is carried out mainly by the inhibition of dNTP's phosphatases and in less extent by the means of reaction dNDP leads to dNTP. Besides that, ATP partially suppresses 3' leads to 5' exonuclease of chromatin which degrades the nascent DNA. The activating action of ATP is connected neither with phosphorylation of histones, nor with the activities of ATP-dependent endo- or exonucleases, DNA gyrase, polynucleotide ligase, or DNA unwinding protein.
Mol Biol (Mosk)
PMID:[Mechanism of activating action of ATP on repair synthesis of DNA in chromatin]. 625 23

The twisting potential of DNA has been determined directly by a method that measures the cyclization probability or j-factor of EcoRI restriction fragments as a function of DNA twist. The cyclization probability is proportional to Kc, the equilibrium constant for cyclization of the restriction fragment via its cohesive ends (Shore et al., 1981). Here we vary the twist of the DNA by making small internal additions to or deletions from a 242 bp EcoRI restriction fragment. A series of 12 DNA molecules has been studied, which range in length from 237 to 254 bp. The cyclization probability is measured from the rates of covalent closure by phage T4 DNA ligase of two systems: (1) a linear restriction fragment in equilibrium with its cyclized form and (2) half molecules (cut by a blunt-end endonuclease) in equilibrium with joined half molecules. The striking result is that, in this DNA size range, the j-factor depends strongly on the fractional twist: the difference between the total helical twist and the nearest integer. Thus j depends in an oscillatory manner on DNA length between 237 and 254 bp with a period of about 10 bp. These data give the free energy of DNA twisting as a function of twist. The curve of j versus DNA length can be fitted to a harmonic twisting potential with a torsional constant of C = 2.4 X 10(-19) erg cm. This value is in reasonable agreement with different estimates of C made by Barkley & Zimm (1979: C = 1.8 X 10(-19) to 4.1 X 10(-19) erg cm) and is somewhat larger than the value obtained resulting from the kinetics of DNA twisting measured by fluorescence depolarization of ethidium intercalated into DNA (C = 1.4 X 10(-19) erg cm; Millar et al., 1982; Thomas et al., 1980) or from spin label studies (Hurley et al., 1982). Our experiments provide a direct measurement of the torsional free energy and they show that the DNA twisting potential is symmetric. Our experiments also indicate that the DNA helix is continuous, or nearly so, in a nicked circle; presumably this happens because the DNA stacking interaction maintains the double helix in register across a single-strand nick. As a consequence, the twist of a singly nicked DNA circle is integral for small (approximately equal to 250 bp) planar DNA circles and there is a change in twist upon cyclization.(ABSTRACT TRUNCATED AT 400 WORDS)
J Mol Biol 1983 Nov 15
PMID:Energetics of DNA twisting. I. Relation between twist and cyclization probability. 631 55

The drug hydroxyurea has been found to affect the conditional DNA ligase mutant cdc9 in the same way as a wild type. Specific concentrations inhibit the joining of completed replicons leading to a substantial accumulation of these molecules. Upon removal of hydroxyurea and further incubation of cdc9 cells at the permissive temperature the replicons joined together, while in sharp contrast at the restrictive temperature no such joining occurred. However, a revertant of cdc9 able to grow at the restrictive temperature was also able to join replicons under these conditions, so the cdc9 ligase must be responsible for the assembly of completed replicons.
Mol Gen Genet 1983
PMID:The cdc9 ligase joins completed replicons in baker's yeast. 634 75


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