Linked Life Data

15830206

Source:http://linkedlifedata.com/resource/pubmed/id/15830206

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-7-15
pubmed:abstractText
Human DNA topoisomerase I is an essential enzyme involved in resolving the torsional stress associated with DNA replication, transcription, and chromatin condensation. The catalytic cycle of the enzyme consists of DNA cleavage to form a covalent enzyme-DNA intermediate, DNA relaxation, and finally, re-ligation of the phosphate backbone to restore the continuity of the DNA. Structure/function studies have elucidated a flexible enzyme that relaxes DNA through coordinated, controlled movements of distinct enzyme domains. The cellular roles of topoisomerase I are apparent throughout the nucleus, but the concentration of processes acting on ribosomal DNA results in topoisomerase I accumulation in the nucleolus. Although the activity of topoisomerase I is required in these processes, the enzyme can also have a deleterious effect on cells. In the event that the final re-ligation step of the reaction cycle is prevented, the covalent topoisomerase I-DNA intermediate becomes a toxic DNA lesion that must be repaired. The complexities of the relaxation reaction, the cellular roles, and the pathways that must exist to repair topoisomerase I-mediated DNA damage highlight the importance of continued study of this essential enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0009-5915
pubmed:author
pubmed:issnType
Print
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
75-85
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Human DNA topoisomerase I: relaxation, roles, and damage control.
pubmed:affiliation
Department of Microbiology, School of Medicine, University of Washington, P.O. Box 357242, 1959 N.E. Pacific St., Seattle, WA 98195-7242, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Review, Research Support, N.I.H., Extramural