View source for 4rg8


==Structural and biochemical studies of a moderately thermophilic Exonuclease I from Methylocaldum szegediense==
<StructureSection load='4rg8' size='340' side='right'caption='[[4rg8]], [[Resolution|resolution]] 2.12&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4rg8]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Methylocaldum_szegediense Methylocaldum szegediense]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4RG8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4RG8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.12&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></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=4rg8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4rg8 OCA], [https://pdbe.org/4rg8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4rg8 RCSB], [https://www.ebi.ac.uk/pdbsum/4rg8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4rg8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A0A0R5X6_9GAMM A0A0A0R5X6_9GAMM] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
A novel exonuclease, designated as MszExo I, was cloned from Methylocaldum szegediense, a moderately thermophilic methanotroph. It specifically digests single-stranded DNA in the 3' to 5' direction. The protein is composed of 479 amino acids, and it shares 47% sequence identity with E. coli Exo I. The crystal structure of MszExo I was determined to a resolution of 2.2 A and it aligns well with that of E. coli Exo I. Comparative studies revealed that MszExo I and E. coli Exo I have similar metal ion binding affinity and similar activity at mesophilic temperatures (25-47 degrees C). However, the optimum working temperature of MszExo I is 10 degrees C higher, and the melting temperature is more than 4 degrees C higher as evaluated by both thermal inactivation assays and DSC measurements. More importantly, two thermal transitions during unfolding of MszExo I were monitored by DSC while only one transition was found in E. coli Exo I. Further analyses showed that magnesium ions not only confer structural stability, but also affect the unfolding of MszExo I. MszExo I is the first reported enzyme in the DNA repair systems of moderately thermophilic bacteria, which are predicted to have more efficient DNA repair systems than mesophilic ones.

Structural and biochemical studies of a moderately thermophilic exonuclease I from Methylocaldum szegediense.,Fei L, Tian S, Moysey R, Misca M, Barker JJ, Smith MA, McEwan PA, Pilka ES, Crawley L, Evans T, Sun D PLoS One. 2015 Feb 6;10(2):e0117470. doi: 10.1371/journal.pone.0117470., eCollection 2015. PMID:25658953<ref>PMID:25658953</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4rg8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Exonuclease 3D structures|Exonuclease 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Methylocaldum szegediense]]
[[Category: Barker JJ]]
[[Category: Crawley L]]
[[Category: Evans T]]
[[Category: Fei L]]
[[Category: McEwan PA]]
[[Category: Misca M]]
[[Category: Moysey R]]
[[Category: Pilka ES]]
[[Category: Smith MA]]
[[Category: Sun D]]
[[Category: Tian S]]