2z1h: Difference between revisions

Revision as of 19:49, 4 May 2008

Crystal structure of E.coli RNase HI surface charged mutant(Q4R/T92K/Q105K/Q113R/Q115K/N143K/T145K)

OverviewOverview

Using the information from the genome projects, recent comparative studies of thermostable proteins have revealed a certain trend of amino acid composition in which polar residues are scarce and charged residues are rich on the protein surface. To clarify experimentally the effect of the amino acid composition of surface residues on the thermostability of Escherichia coli Ribonuclease HI (RNase HI), we constructed six variants in which five to eleven polar residues were replaced by charged residues (5C, 7Ca, 7Cb, 9Ca, 9Cb and 11C). The thermal denaturation experiments indicated that all of the variant proteins are 3.2-10.1 degrees C in Tm less stable than the wild proteins. The crystal structures of resultant protein variants 7Ca, 7Cb, 9Ca and 11C closely resemble that of E. coli RNase HI in their global fold, and several different hydrogen bonding and ion-pair interactions are formed by the mutations. Comparison of the crystal structures of these variant proteins with that of E. coli RNase HI reveals that thermal destabilization is apparently related to electrostatic repulsion of the charged residues with neighbours. This result suggests that charged residues of natural thermostable proteins are strictly posted on the surface with optimal interactions and without repulsive interactions.

About this StructureAbout this Structure

2Z1H is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

Protein thermostabilization requires a fine-tuned placement of surface-charged residues., You DJ, Fukuchi S, Nishikawa K, Koga Y, Takano K, Kanaya S, J Biochem. 2007 Oct;142(4):507-16. Epub 2007 Aug 30. PMID:17761696 Page seeded by OCA on Sun May 4 19:49:42 2008

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OCA

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 [[Image:2z1h.jpg|left|200px]]
- {{Structure
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+The line below this paragraph, containing "STRUCTURE_2z1h", creates the "Structure Box" on the page.
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+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <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>
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-|GENE=
+-->
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-|RELATEDENTRY=[[2z1g|2Z1G]], [[2z1i|2Z1I]], [[2z1j|2Z1J]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2z1h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2z1h OCA], [http://www.ebi.ac.uk/pdbsum/2z1h PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2z1h RCSB]</span>
-}}
 '''Crystal structure of E.coli RNase HI surface charged mutant(Q4R/T92K/Q105K/Q113R/Q115K/N143K/T145K)'''
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 [[Category: Takano, K.]]
 [[Category: You, D J.]]
-[[Category: hydrolase]]
+[[Category: Hydrolase]]
-[[Category: rnase hi]]
+[[Category: Rnase hi]]
-[[Category: surface-charge residue]]
+[[Category: Surface-charge residue]]
-[[Category: thermostability]]
+[[Category: Thermostability]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 19:49:42 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 05:17:27 2008''