1hg3
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Comparative structural studies on proteins derived from organisms with, growth optima ranging from 15 to 100 degrees C are beginning to shed light, on the mechanisms of protein thermoadaptation. One means of sustaining, hyperthermostability is for proteins to exist in higher oligomeric forms, than their mesophilic homologues. Triosephosphate isomerase (TIM) is one, of the most studied enzymes, whose fold represents one of nature's most, common protein architectures. Most TIMs are dimers of approximately 250, amino acid residues per monomer. Here, we report the 2.7 A resolution, crystal structure of the extremely thermostable TIM from Pyrococcus, woesei, a hyperthermophilic archaeon growing optimally at 100 degrees C, representing the first archaeal TIM structure. P. woesei TIM exists as ... | + | Comparative structural studies on proteins derived from organisms with, growth optima ranging from 15 to 100 degrees C are beginning to shed light, on the mechanisms of protein thermoadaptation. One means of sustaining, hyperthermostability is for proteins to exist in higher oligomeric forms, than their mesophilic homologues. Triosephosphate isomerase (TIM) is one, of the most studied enzymes, whose fold represents one of nature's most, common protein architectures. Most TIMs are dimers of approximately 250, amino acid residues per monomer. Here, we report the 2.7 A resolution, crystal structure of the extremely thermostable TIM from Pyrococcus, woesei, a hyperthermophilic archaeon growing optimally at 100 degrees C, representing the first archaeal TIM structure. P. woesei TIM exists as a, tetramer comprising monomers of only 228 amino acid residues. Structural, comparisons with other less thermostable TIMs show that although the, central beta-barrel is largely conserved, severe pruning of several, helices and truncation of some loops give rise to a much more compact, monomer in the small hyperthermophilic TIM. The classical TIM dimer, formation is conserved in P. woesei TIM. The extreme thermostability of, PwTIM appears to be achieved by the creation of a compact tetramer where, two classical TIM dimers interact via an extensive hydrophobic interface., The tetramer is formed through largely hydrophobic interactions between, some of the pruned helical regions. The equivalent helical regions in less, thermostable dimeric TIMs represent regions of high average temperature, factor. The PwTIM seems to have removed these regions of potential, instability in the formation of the tetramer. This study of PwTIM provides, further support for the role of higher oligomerisation states in extreme, thermal stabilisation. |
==About this Structure== | ==About this Structure== | ||
| - | 1HG3 is a | + | 1HG3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_woesei Pyrococcus woesei] with 3PP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Triose-phosphate_isomerase Triose-phosphate isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.1 5.3.1.1] Structure known Active Sites: PP1, PP2, PP3, PP4, PP5, PP6, PP7 and PP8. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1HG3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: triosephosphate isomerase]] | [[Category: triosephosphate isomerase]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:31:29 2007'' |
Revision as of 10:26, 5 November 2007
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CRYSTAL STRUCTURE OF TETRAMERIC TIM FROM PYROCOCCUS WOESEI.
Overview
Comparative structural studies on proteins derived from organisms with, growth optima ranging from 15 to 100 degrees C are beginning to shed light, on the mechanisms of protein thermoadaptation. One means of sustaining, hyperthermostability is for proteins to exist in higher oligomeric forms, than their mesophilic homologues. Triosephosphate isomerase (TIM) is one, of the most studied enzymes, whose fold represents one of nature's most, common protein architectures. Most TIMs are dimers of approximately 250, amino acid residues per monomer. Here, we report the 2.7 A resolution, crystal structure of the extremely thermostable TIM from Pyrococcus, woesei, a hyperthermophilic archaeon growing optimally at 100 degrees C, representing the first archaeal TIM structure. P. woesei TIM exists as a, tetramer comprising monomers of only 228 amino acid residues. Structural, comparisons with other less thermostable TIMs show that although the, central beta-barrel is largely conserved, severe pruning of several, helices and truncation of some loops give rise to a much more compact, monomer in the small hyperthermophilic TIM. The classical TIM dimer, formation is conserved in P. woesei TIM. The extreme thermostability of, PwTIM appears to be achieved by the creation of a compact tetramer where, two classical TIM dimers interact via an extensive hydrophobic interface., The tetramer is formed through largely hydrophobic interactions between, some of the pruned helical regions. The equivalent helical regions in less, thermostable dimeric TIMs represent regions of high average temperature, factor. The PwTIM seems to have removed these regions of potential, instability in the formation of the tetramer. This study of PwTIM provides, further support for the role of higher oligomerisation states in extreme, thermal stabilisation.
About this Structure
1HG3 is a Single protein structure of sequence from Pyrococcus woesei with 3PP as ligand. Active as Triose-phosphate isomerase, with EC number 5.3.1.1 Structure known Active Sites: PP1, PP2, PP3, PP4, PP5, PP6, PP7 and PP8. Full crystallographic information is available from OCA.
Reference
Tiny TIM: a small, tetrameric, hyperthermostable triosephosphate isomerase., Walden H, Bell GS, Russell RJ, Siebers B, Hensel R, Taylor GL, J Mol Biol. 2001 Mar 2;306(4):745-57. PMID:11243785
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