Nonrandom substitution of 2-aminopurine for adenine during deoxyribonucleic acid synthesis in vitro

Biochemistry ◽  
1981 ◽  
Vol 20 (21) ◽  
pp. 6235-6244 ◽  
Author(s):  
Reynaldo C. Pless ◽  
Lore M. Levitt ◽  
Maurice J. Bessman
1979 ◽  
Vol 178 (3) ◽  
pp. 621-626 ◽  
Author(s):  
J F Burke ◽  
P M Duff ◽  
C K Pearson

In order to ascertain the identity of the DNA-dependent DNA polymerase responsible for the observed DNA synthesis in nuclei isolated from baby-hamster kidney (BHK-21/C13) cells a comparative study was carried out on the effects of some drugs, reported to influence DNA synthesis, on DNA synthesis catalysed by these nuclei and by partially purified DNA polymerase-alpha and -beta. In all cases DNA synthesis by isolated nuclei and polymerase-alpha was inhibited to similar extents by N-ethylmaleimide, p-hydroxymercuribenzoate, novobiocin, heparin and phosphonoacetic acid; polymerase-beta was much less affected by these compounds. Ethidium bromide inhibited all DNA synthesis to similar extents, although at low concentrations (about 2 microgram/ml) synthesis in isolated nuclei was stimulated. The results are discussed in relation to the proposal that DNA polymerase-alpha catalyses the covalent extension of Okazaki fragments that these nuclei carry out in vitro.


1971 ◽  
Vol 121 (5) ◽  
pp. 803-809 ◽  
Author(s):  
M. A. Waqar ◽  
L. A. Burgoyne ◽  
M. R. Atkinson

The properties of a nuclear preparation from rat liver and thymus are described. (1) Nearest-neighbour analysis after incorporation of 32P-labelled nucleotide residues from dATP, dCTP, dGTP, dTTP and arabinofuranosyl analogues of CTP and ATP shows template-dependent DNA synthesis. (2) Where primer termini are limiting, incorporation of arabinofuranosyl analogues of AMP and CMP residues proceeds to a limit indicating that both of these analogues are DNA chain terminators. (3) No large differences have been found between the priming potentialities or the intrinsic DNA polymerase activities of nuclei from resting or regenerating liver and the relationship of this DNA synthesis in vitro to DNA replication or repair in vivo is briefly discussed.


1972 ◽  
Vol 130 (4) ◽  
pp. 959-964 ◽  
Author(s):  
Leigh A. Burgoyne

During the evaluation of a method of preparing permealysed Ehrlich ascites cells, shortterm labelling experiments were carried out with d[3H]TTP. In the first minute the bulk of the label appeared as low-molecular-weight pieces of DNA. Subsequently the label appeared in DNA of much higher molecular weight. A brief description of the preparation procedure and the properties of the product is provided. Evidence is presented to show that the nucleotide was incorporated directly without intermediate conversion into dTMP or thymidine.


1963 ◽  
Vol 41 (11) ◽  
pp. 2343-2351 ◽  
Author(s):  
S. Mak ◽  
J. E. Till

The use of isotopically labeled 5-iodo-2′-deoxyuridine (I125UdR) for determination of the rate of deoxyribonucleic acid synthesis in mammalian cells in vitro has been investigated. The results obtained indicate that for this purpose I125UdR is a suitable substitute for the more commonly used DNA precursor, tritium-labeled thymidine (H3TdR). I125UdR appears to be incorporated specifically into the DNA of cells in culture, and has been demonstrated to compete with H3TdR, although the Km for H3TdR was smaller than that of I125UdR by a factor of approximately 4. The amount of label incorporated into DNA of cells increased linearly with time. When the rate of DNA synthesis was reduced by exposure of the cells to various doses of X-rays, the ratio of I125UdR incorporation to H3TdR incorporation into DNA of cells was found to be a constant, which supports the view that uptake of the analogue provides as reliable an indication of effects upon the rate of DNA synthesis as does that of H3TdR. The chief advantage of I125UdR over H3TdR is that I125 is a gamma emitter, so that the difficulties encountered in detection of the low energy beta particles from H3 may be avoided.


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