In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 100, No. 19 ( 2003-09-16), p. 10629-10634
Abstract:
Type IIA topoisomerases both manage the topological state of chromosomal DNA and are the targets of a variety of clinical agents. Bisdioxopiperazines are anticancer agents that associate with ATP-bound eukaryotic topoisomerase II (topo II) and convert the enzyme into an inactive, salt-stable clamp around DNA. To better understand both topo II and bisdioxopiperazine function, we determined the structures of the adenosine 5′-[β,γ-imino]-triphosphate-bound yeast topo II ATPase region ( Sc T2-ATPase) alone and complexed with the bisdioxopiperazine ICRF-187. The drug-free form of the protein is similar in overall fold to the equivalent region of bacterial gyrase but unexpectedly displays significant conformational differences. The ternary drug-bound complex reveals that ICRF-187 acts by an unusual mechanism of inhibition in which the drug does not compete for the ATP-binding pocket, but bridges and stabilizes a transient dimer interface between two ATPase protomers. Our data explain why bisdioxopiperazines target ATP-bound topo II, provide a structural rationale for the effects of certain drug-resistance mutations, and point to regions of bisdioxopiperazines that might be modified to improve or alter drug specificity.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.1832879100
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2003
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
