TY - JOUR
T1 - Characterization of a unique type IA topoisomerase in Bacillus cereus
AU - Li, Zhiyu
AU - Hiasa, Hiroshi
AU - DiGate, Russell
PY - 2006/4
Y1 - 2006/4
N2 - Bacillus cereus topoisomerase IIIβ (bcTopo IIIβ) has been cloned, overexpressed and biochemically characterized. This enzyme exhibits 64% and 33% sequence identity to Bacillus subtilis topoisomerase III (bsTopo III) and Escherichia coli topoisomerase III (ecTopo III) respectively. The enzymatic properties of bcTopo IIIβ differ substantially from other bacterial type IA topoisomerases, including E. coli type IA topoisomerases and B. cereus topoisomerase I (bcTopo I) and IIIα (bcTopo IIIα). bcTopo IIIβ only partially relaxes negatively supercoiled DNA and appears incapable of generating fully relaxed topoisomers. In contrast to ecTopo III and bcTopo IIIα, bcTopo IIIβ is not a decatenase. bcTopo IIIβ is unable to compensate the loss of ecTopo III in vivo. Therefore, bcTopo IIIβ is a unique prokaryotic type IA topoisomerase that is different from previously characterized topoisomerases.
AB - Bacillus cereus topoisomerase IIIβ (bcTopo IIIβ) has been cloned, overexpressed and biochemically characterized. This enzyme exhibits 64% and 33% sequence identity to Bacillus subtilis topoisomerase III (bsTopo III) and Escherichia coli topoisomerase III (ecTopo III) respectively. The enzymatic properties of bcTopo IIIβ differ substantially from other bacterial type IA topoisomerases, including E. coli type IA topoisomerases and B. cereus topoisomerase I (bcTopo I) and IIIα (bcTopo IIIα). bcTopo IIIβ only partially relaxes negatively supercoiled DNA and appears incapable of generating fully relaxed topoisomers. In contrast to ecTopo III and bcTopo IIIα, bcTopo IIIβ is not a decatenase. bcTopo IIIβ is unable to compensate the loss of ecTopo III in vivo. Therefore, bcTopo IIIβ is a unique prokaryotic type IA topoisomerase that is different from previously characterized topoisomerases.
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U2 - 10.1111/j.1365-2958.2006.05070.x
DO - 10.1111/j.1365-2958.2006.05070.x
M3 - Article
C2 - 16556226
AN - SCOPUS:33644847122
SN - 0950-382X
VL - 60
SP - 140
EP - 151
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 1
ER -