1g8y

<StructureSection load='1g8y' size='340' side='right' caption='[[1g8y]], [[Resolution|resolution]] 2.40&Aring;' scene=''>

<table><tr><td colspan='2'>[[1g8y]] is a 12 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1G8Y OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1G8Y FirstGlance]. <br>

</td></tr><tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">REPA ON PLASMID INCQ RSF1010 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr>

<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1g8y FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g8y OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1g8y RCSB], [http://www.ebi.ac.uk/pdbsum/1g8y PDBsum]</span></td></tr>

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<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/g8/1g8y_consurf.spt"</scriptWhenChecked>

</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

Unwinding of double-stranded DNA into single-stranded intermediates required for various fundamental life processes is catalyzed by helicases, a family of mono-, di- or hexameric motor proteins fueled by nucleoside triphosphate hydrolysis. The three-dimensional crystal structure of the hexameric helicase RepA encoded by plasmid RSF1010 has been determined by X-ray diffraction at 2.4 A resolution. The hexamer shows an annular structure with 6-fold rotational symmetry and a approximately 17 A wide central hole, suggesting that single-stranded DNA may be threaded during unwinding. Homologs of all five conserved sequence motifs of the DnaB-like helicase family are found in RepA, and the topography of the monomer resembles RecA and the helicase domain of the bacteriophage T7 gp4 protein. In a modeled complex, ATP molecules are located at the subunit interfaces and clearly define adenine-binding and ATPase catalytic sites formed by amino acid residues located on adjacent monomers; most remarkable is the "arginine finger" Arg207 contributing to the active site in the adjacent monomer. This arrangement of active-site residues suggests cooperativity between monomers in ATP hydrolysis and helicase activity of RepA. The mechanism of DNA unwinding remains elusive, as RepA is 6-fold symmetric, contrasting the recently published asymmetric structure of the bacteriophage T7 gp4 helicase domain.

Crystal structure of the hexameric replicative helicase RepA of plasmid RSF1010.,Niedenzu T, Roleke D, Bains G, Scherzinger E, Saenger W J Mol Biol. 2001 Feb 23;306(3):479-87. PMID:11178907<ref>PMID:11178907</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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*[[Helicase|Helicase]]

[[Category: Bains, G.]]

[[Category: Niedenzu, T.]]

[[Category: Roeleke, D.]]

[[Category: Saenger, W.]]

[[Category: Scherzinger, E.]]

[[Category: Transcription]]