Positively supercoiled DNA in a virus-like particle of an archaebacterium

The topological state of DNA is of importance in a variety of essential biological events 1–4 . Covalently closed circular DNA duplexes isolated from eukaryotic cells and their viruses, as well as from eubacteria and their bacteriophages are, without exception, negatively supercoiled. Little is know...

Full description

Saved in:
Bibliographic Details
Published in:Nature (London) 1986-05, Vol.321 (6067), p.256-258
Main Authors: Nadal, Marc, Mirambeau, Gilles, Forterre, Patrick, Reiter, Wolf-Dieter, Duguet, Michel
Format: Article
Language:English
Subjects:
archaebacteria
Humanities and Social Sciences
letter
multidisciplinary
Science
Science (multidisciplinary)
Sulfolobus
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The topological state of DNA is of importance in a variety of essential biological events 1–4 . Covalently closed circular DNA duplexes isolated from eukaryotic cells and their viruses, as well as from eubacteria and their bacteriophages are, without exception, negatively supercoiled. Little is known about the topological state of the DNA in archaebacteria, a group of organisms distinct from both ekaryotes and eubacteria 5 , but recently an ATP-dependent DNA topoisomerase has been isolated from the archaebacterium Sulfolobus acidocaldarius . This enzyme, termed ‘reverse gyrase’, converts relaxed or negatively supercoiled DNA into positively supercoiled forms in vitro 6–9 . It is not a gyrase-like type II topoisomerase, as initially reported 9 , but an ATP-dependent type I enzyme 7,8 . The function of this enzyme in vivo has not been established, largely because of the lack of data on the topological state of Sulfolobus DNA. Here we show that DNA exists in a positively superhelical state in the genome of the virus-like particle SSV-1, present in Sulfolobus .
ISSN:0028-0836
1476-4687
DOI:10.1038/321256a0