Linked Life Data

16611245

Source:http://linkedlifedata.com/resource/pubmed/id/16611245

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-4-13
pubmed:abstractText
In Escherichia coli, ATP-DnaA, but not ADP-DnaA, forms an initiation complex that undergoes site-specific duplex DNA unwinding, open complex formation. However, it remains unclear how highly the ATP-dependent activation of the initiation factor is conserved in evolution. The hyperthermophile Thermotoga maritima is one of the most ancient eubacteria in evolution. Here, we show that the DnaA homolog (tmaDnaA) of this bacterium forms open complexes with the predicted origin region (tma-oriC) in vitro. TmaDnaA has a strong and specific affinity for ATP/ADP as well as for 12-mer repeating sequences within the tma-oriC. Unlike ADP-tmaDnaA, ATP-tmaDnaA is highly cooperative in DNA binding and forms open complexes in a manner that depends on temperature and the superhelical tension of the tma-oriC-bearing plasmid. The minimal tma-oriC required for unwinding is a 149-bp region containing five repeats of the 12-mer sequence and two AT-rich 9-mer repeats. TmaDnaA-binding to the 12-mer motif provokes DNA bending. The 9-mer region is the duplex-unwinding site. The tmaDnaA-binding and unwinding motifs of tma-oriC share sequence homology with corresponding archaeal and eukaryotic sequences. These findings suggest that the ATP-dependent molecular switch of the initiator and the mechanisms in the replication initiation complex are highly conserved in eubacterial evolution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1356-9597
pubmed:author
pubmed:issnType
Print
pubmed:volume
11
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-38
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
The DnaA homolog of the hyperthermophilic eubacterium Thermotoga maritima forms an open complex with a minimal 149-bp origin region in an ATP-dependent manner.
pubmed:affiliation
Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't