1dl3: Difference between revisions
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[[Image:1dl3.gif|left|200px]] | [[Image:1dl3.gif|left|200px]] | ||
'''CRYSTAL STRUCTURE OF MUTUALLY GENERATED MONOMERS OF DIMERIC PHOSPHORIBOSYLANTRANILATE ISOMERASE FROM THERMOTOGA MARITIMA''' | {{Structure | ||
|PDB= 1dl3 |SIZE=350|CAPTION= <scene name='initialview01'>1dl3</scene>, resolution 2.7Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | |||
|ACTIVITY= [http://en.wikipedia.org/wiki/Phosphoribosylanthranilate_isomerase Phosphoribosylanthranilate isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.24 5.3.1.24] | |||
|GENE= | |||
}} | |||
'''CRYSTAL STRUCTURE OF MUTUALLY GENERATED MONOMERS OF DIMERIC PHOSPHORIBOSYLANTRANILATE ISOMERASE FROM THERMOTOGA MARITIMA''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1DL3 is a [ | 1DL3 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DL3 OCA]. | ||
==Reference== | ==Reference== | ||
Structure and function of mutationally generated monomers of dimeric phosphoribosylanthranilate isomerase from Thermotoga maritima., Thoma R, Hennig M, Sterner R, Kirschner K, Structure. 2000 Mar 15;8(3):265-76. PMID:[http:// | Structure and function of mutationally generated monomers of dimeric phosphoribosylanthranilate isomerase from Thermotoga maritima., Thoma R, Hennig M, Sterner R, Kirschner K, Structure. 2000 Mar 15;8(3):265-76. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10745009 10745009] | ||
[[Category: Phosphoribosylanthranilate isomerase]] | [[Category: Phosphoribosylanthranilate isomerase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: x-ray structure]] | [[Category: x-ray structure]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:40:10 2008'' | ||
Revision as of 11:40, 20 March 2008
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| , resolution 2.7Å | |||||||
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| Ligands: | |||||||
| Activity: | Phosphoribosylanthranilate isomerase, with EC number 5.3.1.24 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF MUTUALLY GENERATED MONOMERS OF DIMERIC PHOSPHORIBOSYLANTRANILATE ISOMERASE FROM THERMOTOGA MARITIMA
OverviewOverview
BACKGROUND: Oligomeric proteins may have been selected for in hyperthermophiles because subunit association provides extra stabilization. Phosphoribosylanthranilate isomerase (PRAI) is monomeric and labile in most mesophilic microorganisms, but dimeric and stable in the hyperthermophile Thermotoga maritima (tPRAI). The two subunits of tPRAI are associated back-to-back and are locked together by a hydrophobic loop. The hypothesis that dimerization is important for thermostability has been tested by rationally designing monomeric variants of tPRAI. RESULTS: The comparison of tPRAI and PRAI from Escherichia coli (ePRAI) suggested that levelling the nonplanar dimer interface would weaken the association. The deletion of two residues in the loop loosened the dimer. Subsequent filling of the adjacent pocket and the exchange of polar for apolar residues yielded a weakly associating and a nonassociating monomeric variant. Both variants are as active as the parental dimer but far more thermolabile. The thermostability of the weakly associating monomer increased significantly with increasing protein concentration. The X-ray structure of the nonassociating monomer differed from that of the parental subunit only in the restructured interface. The orientation of the original subunits was maintained in a crystal contact between two monomers. CONCLUSIONS: tPRAI is dimeric for reasons of stability. The clearly separated responsibilities of the betaalpha loops, which are involved in activity, and the alphabeta loops, which are involved in protein stability, has permitted the evolution of dimers without compromising their activity. The preserved interaction in the crystal contacts suggests the most likely model for dimer evolution.
About this StructureAbout this Structure
1DL3 is a Single protein structure of sequence from Thermotoga maritima. Full crystallographic information is available from OCA.
ReferenceReference
Structure and function of mutationally generated monomers of dimeric phosphoribosylanthranilate isomerase from Thermotoga maritima., Thoma R, Hennig M, Sterner R, Kirschner K, Structure. 2000 Mar 15;8(3):265-76. PMID:10745009
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