1vjw: Difference between revisions
New page: left|200px<br /><applet load="1vjw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vjw, resolution 1.75Å" /> '''STRUCTURE OF OXIDORE... |
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[[Image:1vjw.gif|left|200px]]<br /><applet load="1vjw" size=" | [[Image:1vjw.gif|left|200px]]<br /><applet load="1vjw" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1vjw, resolution 1.75Å" /> | caption="1vjw, resolution 1.75Å" /> | ||
'''STRUCTURE OF OXIDOREDUCTASE (NADP+(A),FERREDOXIN(A))'''<br /> | '''STRUCTURE OF OXIDOREDUCTASE (NADP+(A),FERREDOXIN(A))'''<br /> | ||
==Overview== | ==Overview== | ||
BACKGROUND: The characterization of the structural features that account | BACKGROUND: The characterization of the structural features that account for the high thermostability of some proteins is of great scientific and biotechnological interest. Proteins from hyperthermophilic organisms with optimum growth temperatures of 80 degrees C and higher generally show high intrinsic stabilities. The comparison of high resolution X-ray structures of these proteins with their counterparts from mesophilic organisms has therefore helped to identify potentially stabilizing forces in a number of cases. Small monomeric proteins which comprise only a single domain, such as ferredoxins, are especially suitable for such comparisons since the search for determinants of protein stability is considerably simplified. RESULTS: The 1.75 A crystal structure of the extremely thermostable 1[4Fe-4S] ferredoxin from Thermotoga maritima (FdTm) was determined and compared with other monocluster-containing ferredoxins with different degrees of thermostability. CONCLUSIONS: A comparison of the three-dimensional structure of FdTm with that of ferredoxins from mesophilic organisms suggests that the very high thermostability of FdTm is unexpectedly achieved without large changes of the overall protein structure. Instead, an increased number of potentially stabilizing features is observed in FdTm, compared with mesophilic ferredoxins. These include stabilization of alpha helices, replacement of residues in strained conformation by glycines, strong docking of the N-terminal methionine and an overall increase in the number of hydrogen bonds. Most of these features stabilize several secondary structure elements and improve the overall rigidity of the polypeptide backbone. The decreased flexibility will certainly play a relevant role in shielding the iron-sulfur cluster against physiologically high temperatures and further improve the functional integrity of FdTm. | ||
==About this Structure== | ==About this Structure== | ||
1VJW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima] with SF4 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1VJW is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima] with <scene name='pdbligand=SF4:'>SF4</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VJW OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: thermostable]] | [[Category: thermostable]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:36:03 2008'' | ||
Revision as of 16:36, 21 February 2008
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STRUCTURE OF OXIDOREDUCTASE (NADP+(A),FERREDOXIN(A))
OverviewOverview
BACKGROUND: The characterization of the structural features that account for the high thermostability of some proteins is of great scientific and biotechnological interest. Proteins from hyperthermophilic organisms with optimum growth temperatures of 80 degrees C and higher generally show high intrinsic stabilities. The comparison of high resolution X-ray structures of these proteins with their counterparts from mesophilic organisms has therefore helped to identify potentially stabilizing forces in a number of cases. Small monomeric proteins which comprise only a single domain, such as ferredoxins, are especially suitable for such comparisons since the search for determinants of protein stability is considerably simplified. RESULTS: The 1.75 A crystal structure of the extremely thermostable 1[4Fe-4S] ferredoxin from Thermotoga maritima (FdTm) was determined and compared with other monocluster-containing ferredoxins with different degrees of thermostability. CONCLUSIONS: A comparison of the three-dimensional structure of FdTm with that of ferredoxins from mesophilic organisms suggests that the very high thermostability of FdTm is unexpectedly achieved without large changes of the overall protein structure. Instead, an increased number of potentially stabilizing features is observed in FdTm, compared with mesophilic ferredoxins. These include stabilization of alpha helices, replacement of residues in strained conformation by glycines, strong docking of the N-terminal methionine and an overall increase in the number of hydrogen bonds. Most of these features stabilize several secondary structure elements and improve the overall rigidity of the polypeptide backbone. The decreased flexibility will certainly play a relevant role in shielding the iron-sulfur cluster against physiologically high temperatures and further improve the functional integrity of FdTm.
About this StructureAbout this Structure
1VJW is a Single protein structure of sequence from Thermotoga maritima with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Small structural changes account for the high thermostability of 1[4Fe-4S] ferredoxin from the hyperthermophilic bacterium Thermotoga maritima., Macedo-Ribeiro S, Darimont B, Sterner R, Huber R, Structure. 1996 Nov 15;4(11):1291-301. PMID:8939753
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