1f21

<StructureSection load='1f21' size='340' side='right' caption='[[1f21]], [[Resolution|resolution]] 1.40&Aring;' scene=''>

<table><tr><td colspan='2'>[[1f21]] is a 1 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=1F21 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1F21 FirstGlance]. <br>

</td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Ribonuclease_H Ribonuclease H], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.26.4 3.1.26.4] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1f21 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1f21 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1f21 RCSB], [http://www.ebi.ac.uk/pdbsum/1f21 PDBsum]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/f2/1f21_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].

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== Publication Abstract from PubMed ==

Proteins often require cofactors to perform their biological functions and must fold in the presence of their cognate ligands. Using circular dichroism spectroscopy. we investigated the effects of divalent metal binding upon the folding pathway of Escherichia coli RNase HI. This enzyme binds divalent metal in its active site, which is proximal to the folding core of RNase HI as defined by hydrogen/deuterium exchange studies. Metal binding increases the apparent stability of native RNase HI chiefly by reducing the unfolding rate. As with the apo-form of the protein, refolding from high denaturant concentrations in the presence of Mg2+ follows three-state kinetics: formation of a rapid burst phase followed by measurable single exponential kinetics. Therefore, the overall folding pathway of RNase HI is minimally perturbed by the presence of metal ions. Our results indicate that the metal cofactor enters the active site pocket only after the enzyme reaches its native fold, and therefore, divalent metal binding stabilizes the protein by decreasing its unfolding rate. Furthermore, the binding of the cofactor is dependent upon a carboxylate critical for activity (Asp10). A mutation in this residue (D10A) alters the folding kinetics in the absence of metal ions such that they are similar to those observed for the unaltered enzyme in the presence of metal.

Divalent metal cofactor binding in the kinetic folding trajectory of Escherichia coli ribonuclease HI.,Goedken ER, Keck JL, Berger JM, Marqusee S Protein Sci. 2000 Oct;9(10):1914-21. PMID:11106164<ref>PMID:11106164</ref>

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

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*[[Ribonuclease|Ribonuclease]]

[[Category: Ribonuclease H]]

[[Category: Berger, J M]]

[[Category: Goedken, E R]]

[[Category: Keck, J L]]

[[Category: Marqusee, S]]

[[Category: Rnase h*]]