Linked Life Data

10352172

Source:http://linkedlifedata.com/resource/pubmed/id/10352172

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1999-7-26
pubmed:abstractText
Human topoisomerase IIIalpha (hTopo IIIalpha), the recently identified first member of the topoisomerase IA subfamily in humans, has a central domain which is highly homologous to the yeast topoisomerase III, but an overall organization closer to that of Escherichia coli DNA topoisomerase I. In order to determine the properties of hTopo IIIalpha, compared to those of other topoisomerase IA subfamily members, we purified this enzyme to near homogeneity, together with an active site-mutant Y337F. We show that hTopo IIIalpha is able to relax negatively supercoiled DNA in a distributive manner, leading to the total disappearance of the initial substrate and the appearance of intermediate topoisomers. This DNA relaxation activity is magnesium-dependent, although a low concentration of MgCl2is sufficient to obtain efficient catalysis. 32P-transfer experiments demonstrated that hTopo IIIalpha is able to cleave a single-stranded oligonucleotide and to bind covalently to the 5'-end of the cleaved DNA. Addition of 0.5 M NaCl reverses the reaction, leading to the religation of the oligo-nucleotide. Experiments utilizing several different single-stranded oligonucleotides permitted us to map several cleavage sites and to deduce a consensus sequence for DNA cleavage (CANNN downward arrow), which is different from that for other members of the Topo IA subfamily.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0305-1048
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2443-50
pubmed:dateRevised
2008-11-20
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Purification and characterization of human DNA topoisomerase IIIalpha.
pubmed:affiliation
Rhône-Poulenc Rorer, Centre de recherche de Vitry-Alfortville, 13 quai Jules Guesde, BP14, 94403 Vitry sur Seine Cedex, France. helene.goulaouic@rp-rorer.fr
pubmed:publicationType
Journal Article