Binding of the Escherichia coli UvrAB proteins to the DNA mono- and diadducts of cis-[N-2-amino-N-2-methylamino-2,2,1-bicycloheptane]dichloroplatinum(II ) and cisplatin. Analysis of the factors controlling recognition and proof of monoadduct-mediated UvrB-DNA cross-linking.
The interactions of the Escherichia coli endonuclease UvrAB proteins with the DNA mono- and diadducts of both the cis-racemic exo-[N-2-amino-N-2-methylamino-2,2,1-bicycloheptane]dichloroplatin um(II) (complex 1) and cisplatin (cis-diamminedichloroplatinum(II) (cis-DDP)), have been studied. Complex 1 reacts faster with DNA than cis-DDP and gives monoadducts with a longer lifetime (8 h 20 min chelation t 1/2 compared with 2 h 40 min for cis-DDP). Using pSP65 plasmid [3H]DNA, the filter binding assay was associated with the analysis of the nucleoprotein complexes to characterize the UvrAB recognition of the platinum adducts and to demonstrate the occurrence of platinum-mediated DNA-protein cross-linking. First, it is shown that the UvrAB proteins recognize the complex 1 mono- and diadducts with a higher affinity than those of cis-DDP. Fifteen times more cis-DDP adducts per plasmid are required than complex 1 adducts, to lead to similar UvrAB binding. However, the UvrAB proteins recognize monoadducts and diadducts of each complex with a similar affinity. Second, it is shown that UvrB is the protein involved in the nucleo-protein complexes formed from mono- and diadducts of complex 1 and cis-DDP. This protein is also partly cross-linked to DNA with a similar efficiency by monoadducts derived from complex 1 and cis-DDP. However, as UvrB has a greater affinity for the DNA adducts of complex 1 than for those of cis-DDP, more UvrB-platinum-DNA cross-links are formed with complex 1 than with cis-DDP. This study, using a bacterial repair system as a model, points to a possible strategy for making new cytotoxic platinum complexes for mammalian cells.
Lambert
B
B
Institut Gustave Roussy, URA 147 CNRS, U 140 INSERM, Villejuif, France.
Jestin
J L
JL
Bréhin
P
P
Oleykowski
C
C
Yeung
A T
AT
Mailliet
P
P
Prétot
C
C
Le Pecq
J B
JB
Jacquemin-Sablon
A
A
Chottard
J C
JC
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002614:Chelating Agents; D002945:Cisplatin / Q000378:metabolism*; D003432:Cross-Linking Reagents; D018736:DNA Adducts / Q000378:metabolism*; D004265:DNA Helicases; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004492:Edetic Acid; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D007700:Kinetics; D009944:Organoplatinum Compounds / Q000378:metabolism*; D011485:Protein Binding; D012967:Sodium Dodecyl Sulfate
C095675:(N-2-amino-N-2-methylamino-2,2,1-bicycloheptane)dichloroplatinum(II); D001426:Bacterial Proteins; D002614:Chelating Agents; D003432:Cross-Linking Reagents; D018736:DNA Adducts; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D009944:Organoplatinum Compounds; C058093:UvrB protein, E coli; C057270:cisplatin-DNA adduct; D012967:Sodium Dodecyl Sulfate; D004492:Edetic Acid; C068631:UvrA protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D002945:Cisplatin