Linked Life Data

16257971

Source:http://linkedlifedata.com/resource/pubmed/id/16257971

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2005-12-19
pubmed:abstractText
Clamp loaders orchestrate the switch from distributive to processive DNA synthesis. Their importance in cellular processes is underscored by their conservation across all forms of life. Here, we describe a new form of clamp loader from the archaeon Methanosarcina acetivorans. Unlike previously described archaeal clamp loaders, which are composed of one small subunit and one large subunit, the M. acetivorans clamp loader comprises two similar small subunits (M. acetivorans replication factor C small subunit (MacRFCS)) and one large subunit (MacRFCL). The relatedness of the archaeal and eukaryotic clamp loaders (which are made up of four similar small subunits and one large subunit) suggests that the M. acetivorans clamp loader may be an intermediate form in the archaeal/eukaryotic sister lineages. The clamp loader complex reconstituted from the three subunits MacRFCS1, MacRFCS2, and MacRFCL stimulated DNA synthesis by a cognate DNA polymerase in the presence of its sliding clamp. We used site-directed mutagenesis in the Walker A and SRC motifs to examine the contribution of each subunit to the function of the M. acetivorans clamp loader. Although mutations in MacRFCL and MacRFCS2 did not impair clamp loading activity, any mutant clamp loader harboring a mutation in MacRFCS1 was devoid of the clamp loading property. Mac-RFCS1 is therefore critical to the clamp loading activity of the M. acetivorans clamp loader. It is our anticipation that the discovery of this unique replication factor C homolog will lead to critical insights into the evolution of more complex clamp loaders from simpler ones as more complex organisms evolved in the archaeal/eukaryotic sister lineages.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
41852-63
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Biochemical and mutational analyses of a unique clamp loader complex in the archaeon Methanosarcina acetivorans.
pubmed:affiliation
Department of Animal Sciences, University of Illinois at Urbana-Champaign, 61801, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't