Premium
Molecular analysis of mutations induced by the intercalating agent ellipticine at the hisd3052 allele of salmonella typhimurium TA98
Author(s) -
Demarini David M.,
AbuShakra Amal,
Gupta Ranjan,
Hendee Linda J.,
Levine Jessie G.
Publication year - 1992
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.2850200104
Subject(s) - dna gyrase , dna , salmonella , mutant , polymerase chain reaction , chemistry , genetics , microbiology and biotechnology , biology , gene , bacteria , escherichia coli
We have used DNA colony hybridization, the polymerase chain reaction (PCR), and direct DNA sequencing to determine the mutations induced by the intercalating agent ellipticine in Salmonella typhimurium TA98 in the presence of S9. Of 400 ellipticine‐induced revertants that were selected at a mutant yield that was ninefold over the background, 85.5% contained a GC or CG deletion within a common CGCGCGCG hotspot; this deletion occurred among 47% of the spontaneous revertants. In addition to this hotspot, the ellipticine spectrum contained two deletion warmspots that reside opposite each other in looped‐out regions of a possible DNA secondary structure. Ellipticine and its metabolites likely revert Salmonella strain TA98 by forming DNA adducts that promote slippage‐mismatches and by stabilizing these slipped mismatched sequences via intercalation. The involvement of these mechanisms, along with a likely role for DNA secondary structures and a possible role for DNA gyrase, may account for the site specificity exhibited by ellipticine in strain TA98. © 1992 Wiley‐Liss, Inc.