E. Vandenakker et al., THE FORMATION OF ONE-G DELETIONS AS A CONSEQUENCE OF SINGLET-OXYGEN-INDUCED DNA-DAMAGE, Mutation research, 309(1), 1994, pp. 45-52
Single-stranded M13mp10 DNA containing a 144-bp mutational target sequ
ence in the lacZ alpha gene was treated with singlet oxygen (O-1(2)) g
enerated by thermodissociation of the endoperoxide of 3,3'-(1,4-naphth
alene-1,4-diyl)dipropionate (NDPO2). After transfection to non-SOS-ind
uced E. coli cells, 32 mutants preselected for a mutation in the 144-b
p target were collected and analyzed by DNA sequencing. One-G deletion
s represented the predominant type of mutation accounting for 50% of t
he mutations analyzed. The remaining part appeared to consist of base
substitutions, i.e. G --> T transversions (34%), C --> T transitions (
12.5%) and one T --> C transition (3%). Sixty percent of the mutations
were found in two major mutational hotspots. We conclude that the pre
dominant one-G deletions are due to a guanine reaction product which m
ight be specific for O-1(2).