Binding of platinum-diaminonitroxyl complexes to animal DNA.

Reaction of PtII(DAPO)X2 complexes (where DAPO is trans-3,4-diamino-2,2,6,6-tetramethylpiperidine-1-oxyl, X2 = (NO3)2, oxalato (Ox) or 1,1-cyclobutanedicarboxylato (Cbdca)) with a bovine spleen DNA in 0.01 M NaHCO3 at 37 degrees C for 24 h gives rise to formation of platinated DNA. The [bound PtII(DAPO)]/[nucleotide] ratio (r) depends on the initial ratio of the reagents and on the nature of leaving ligands X.

Marker-dependent recombination in T4 bacteriophage. IV. Recombinational effects of antimutator T4 DNA polymerase.

Recombinational effects of the antimutator allele tsL42 of gene 43 of phage T4, encoding DNA polymerase, were studied in crosses between rIIB mutants. Recombination under tsL42-restricted conditions differed from the normal one in several respects: (1) basic recombination was enhanced, especially within very short distances; (2) mismatch repair tracts were shortened, while the contribution of mismatch repair to recombination was not changed; (3) marker interference at very short distances was augmented. We infer that the T4 DNA polymerase is directly involved in mismatch repair, performing both excision of a nonmatched single strand (by its 3'-->5' exonuclease) and filling the resulting gap.