Development of novel inhibitor probes of DNA polymerase III based on dGTP analogs of the HPUra type: base, nucleoside and nucleotide derivatives of N2-(3,4-dichlorobenzyl)guanine.
6-(p-Hydroxyphenylhydrazino)uracil (H2-HPUra) is a selective and potent inhibitor of the replication-specific class III DNA polymerase (pol III) of Gr+ bacteria. Although formally a pyrimidine, H2-HPUra derives its inhibitory activity from its specific capacity to mimic the purine nucleotide, dGTP. We describe the successful conversion of the H2-HPUra inhibitor prototype to a bona fide purine, using N2-(benzyl)guanine (BG) as the basis. Structure-activity relationships of BGs carrying a variety of substituents on the aryl ring identified N2-(3,4-dichlorobenzyl)guanine (DCBG) as a nucleus equivalent to H2-HPUra with respect to potency and inhibitor mechanism. DCBdGTP, the 2'-deoxyribonucleoside 5'-triphosphate form of DCBG, was synthesized and characterized with respect to its action on wild-type and mutant forms of B. subtilis DNA pol III. DCBdGTP acted on pol III by the characteristic inhibitor mechanism and formally occupied the dNTP binding site with a fit which permitted its polymerization.
Butler
M M
MM
Department of Pharmacology, University of Massachusetts Medical School, Worcester 01655.
Dudycz
L W
LW
Khan
N N
NN
Wright
G E
GE
Brown
N C
NC
D001483:Base Sequence; D001665:Binding Sites; D004258:DNA Polymerase III / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003848:Deoxyguanine Nucleotides / Q000378:metabolism / Q000494:pharmacology*; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D014498:Uracil / Q000031:analogs & derivatives* / Q000494:pharmacology
D003848:Deoxyguanine Nucleotides; C066672:N(2)-(3,4-dichlorobenzyl)-2'-deoxyguanosine 5'triphosphate; C066673:N(2)-(3,4-dichlorobenzyl)guanine; C011284:6-(4-hydroxyphenylhydrazino)uracil; D014498:Uracil; D006147:Guanine; C029603:deoxyguanosine triphosphate; D004258:DNA Polymerase III