1xo1
From Proteopedia
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| - | [[Image:1xo1.png|left|200px]] | ||
| - | + | ==T5 5'-EXONUCLEASE MUTANT K83A== | |
| + | <StructureSection load='1xo1' size='340' side='right'caption='[[1xo1]], [[Resolution|resolution]] 2.50Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[1xo1]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_virus_T5 Escherichia virus T5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XO1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XO1 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]] 2.5Å</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=1xo1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xo1 OCA], [https://pdbe.org/1xo1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xo1 RCSB], [https://www.ebi.ac.uk/pdbsum/1xo1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xo1 ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/FEN_BPT5 FEN_BPT5] Catalyzes both the 5'-exonucleolytic and structure-specific endonucleolytic hydrolysis of DNA branched nucleic acid molecules and probably plays a role in viral genome replication (PubMed:9874768, PubMed:15077103, PubMed:10364212). Active on flap (branched duplex DNA containing a free single-stranded 5'-end), 5'overhangs and pseudo-Y structures (PubMed:9874768, PubMed:15077103, PubMed:10364212). The substrates require a free, single-stranded 5' end, with endonucleolytic hydrolysis occurring at the junction of double- and single-stranded DNA (PubMed:9874768). This function may be used for example to trim such branched molecules generated by Okazaki fragments synthesis during replication.[HAMAP-Rule:MF_04140]<ref>PMID:10364212</ref> <ref>PMID:15077103</ref> <ref>PMID:9874768</ref> | ||
| + | == Evolutionary Conservation == | ||
| + | [[Image:Consurf_key_small.gif|200px|right]] | ||
| + | Check<jmol> | ||
| + | <jmolCheckbox> | ||
| + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/xo/1xo1_consurf.spt"</scriptWhenChecked> | ||
| + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
| + | <text>to colour the structure by Evolutionary Conservation</text> | ||
| + | </jmolCheckbox> | ||
| + | </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/main_output.php?pdb_ID=1xo1 ConSurf]. | ||
| + | <div style="clear:both"></div> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | Efficient cellular DNA replication requires the activity of a 5'-3' exonuclease. These enzymes are able to hydrolyze DNA.DNA and RNA.DNA substrates exonucleolytically, and they are structure-specific endonucleases. The 5'-3' exonucleases are conserved in organisms as diverse as bacteriophage and mammals. Crystal structures of three representative enzymes identify two divalent-metal-binding sites typically separated by 8-10 A. Site-directed mutagenesis was used to investigate the roles of three lysine residues (K83, K196, and K215) situated near two metal-binding sites in bacteriophage T5 5'-3' exonuclease. Neither K196 nor K215 was essential for either the exo- or the endonuclease activity, but mutation of these residues increased the dissociation constant for the substrate from 5 nM to 200 nM (K196A) and 50 nM (K215A). Biochemical analysis demonstrated that K83 is absolutely required for exonucleolytic activity on single-stranded DNA but is not required for endonucleolytic cleavage of flap structures. Structural analysis of this mutant by x-ray crystallography showed no significant perturbations around the metal-binding sites in the active site. The wild-type protein has different pH optima for endonuclease and exonuclease activities. Taken together, these results suggest that different mechanisms for endo- and exonucleolytic hydrolysis are used by this multifunctional enzyme. | ||
| - | + | Mutagenesis of conserved lysine residues in bacteriophage T5 5'-3' exonuclease suggests separate mechanisms of endo-and exonucleolytic cleavage.,Garforth SJ, Ceska TA, Suck D, Sayers JR Proc Natl Acad Sci U S A. 1999 Jan 5;96(1):38-43. PMID:9874768<ref>PMID:9874768</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | <div class="pdbe-citations 1xo1" style="background-color:#fffaf0;"></div> | |
| - | + | ||
==See Also== | ==See Also== | ||
| - | *[[Exonuclease|Exonuclease]] | + | *[[Exonuclease 3D structures|Exonuclease 3D structures]] |
| - | + | == References == | |
| - | == | + | <references/> |
| - | < | + | __TOC__ |
| - | [[Category: | + | </StructureSection> |
| - | [[Category: | + | [[Category: Escherichia virus T5]] |
| - | [[Category: | + | [[Category: Large Structures]] |
| - | [[Category: | + | [[Category: Ceska TA]] |
| - | [[Category: | + | [[Category: Sayers JR]] |
| - | + | [[Category: Suck D]] | |
| - | + | ||
Current revision
T5 5'-EXONUCLEASE MUTANT K83A
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