View source for 4aai


==THERMOSTABLE PROTEIN FROM HYPERTHERMOPHILIC VIRUS SSV-RH==
<StructureSection load='4aai' size='340' side='right'caption='[[4aai]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4aai]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Sulfolobus_virus_Ragged_Hills Sulfolobus virus Ragged Hills]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=4a1q 4a1q]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4AAI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4AAI FirstGlance]. <br>
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4aai FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4aai OCA], [https://pdbe.org/4aai PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4aai RCSB], [https://www.ebi.ac.uk/pdbsum/4aai PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4aai ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q6TRU9_9VIRU Q6TRU9_9VIRU] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Hyperthermophilic archaeal viruses, including Sulfolobus spindle-shaped viruses (SSVs) such as SSV-1 and SSV-Ragged Hills, exhibit remarkable morphology and genetic diversity. However, they remain poorly understood, in part because their genomes exhibit limited or unrecognizable sequence similarity to genes with known function. Here we report structural and functional studies of E73, a 73-residue homodimeric protein encoded within the SSV-Ragged Hills genome. Despite lacking significant sequence similarity, the nuclear magnetic resonance (NMR) structure reveals clear similarity to ribbon-helix-helix (RHH) domains present in numerous proteins involved in transcriptional regulation. In vitro double-stranded DNA (dsDNA) binding experiments confirm the ability of E73 to bind dsDNA in a nonspecific manner with micromolar affinity, and characterization of the K11E variant confirms the location of the predicted DNA binding surface. E73 is distinct, however, from known RHH domains. The RHH motif is elaborated upon by the insertion of a third helix that is tightly integrated into the structural domain, giving rise to the "RH3" fold. Within the homodimer, this helix results in the formation of a conserved, symmetric cleft distal to the DNA binding surface, where it may mediate protein-protein interactions or contribute to the high thermal stability of E73. Analysis of backbone amide dynamics by NMR provides evidence of a rigid core, fast picosecond to nanosecond time scale NH bond vector motions for residues located within the antiparallel beta-sheet region of the proposed DNA-binding surface, and slower microsecond to millisecond time scale motions for residues in the alpha1-alpha2 loop. The roles of E73 and its SSV homologues in the viral life cycle are discussed.

Structural Studies of E73 from a Hyperthermophilic Archaeal Virus Identify the "RH3" Domain, an Elaborated Ribbon-Helix-Helix Motif Involved in DNA Recognition.,Schlenker C, Goel A, Tripet BP, Menon S, Willi T, Dlakic M, Young MJ, Lawrence CM, Copie V Biochemistry. 2012 Apr 3;51(13):2899-910. Epub 2012 Mar 22. PMID:22409376<ref>PMID:22409376</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4aai" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Sulfolobus virus Ragged Hills]]
[[Category: Copie V]]
[[Category: Goel A]]
[[Category: Lawrence CM]]
[[Category: Menon S]]
[[Category: Schlenker C]]
[[Category: Tripet BP]]