Stable substructures of eightfold .beta..alpha.-barrel proteins: fragment complementation of phosphoribosylanthranilate isomerase
| العنوان: | Stable substructures of eightfold .beta..alpha.-barrel proteins: fragment complementation of phosphoribosylanthranilate isomerase |
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| المؤلفون: | Joerg Eder, Kasper Kirschner |
| المصدر: | Biochemistry. 31:3617-3625 |
| بيانات النشر: | American Chemical Society (ACS), 1992. |
| سنة النشر: | 1992 |
| مصطلحات موضوعية: | Guanidinium chloride, Protein Conformation, Molecular Sequence Data, Alpha (ethology), Cooperativity, Saccharomyces cerevisiae, Biology, Biochemistry, chemistry.chemical_compound, Multienzyme Complexes, Amino Acid Sequence, Beta (finance), Protein secondary structure, Aldose-Ketose Isomerases, G alpha subunit, Base Sequence, Phosphoribosylanthranilate isomerase, Circular Dichroism, Indole-3-Glycerol-Phosphate Synthase, Peptide Fragments, Complementation, Tetrahydrofolate Dehydrogenase, chemistry, Factor Xa, Electrophoresis, Polyacrylamide Gel, Spectrophotometry, Ultraviolet, Carbohydrate Epimerases, Plasmids |
| الوصف: | The (beta alpha)8 (or "TIM")-barrel protein phosphoribosylanthranilate isomerase from Saccharomyces cerevisiae was cleaved between the sixth and seventh beta alpha module to test the capacity of the resulting fragments to adopt native format autonomously. The fragments, which were expressed from separate coding sequences, were soluble and monomeric. The amino-terminal fragment p1 was compact, possessed an almost nativelike far-UV but a strongly reduced near-UV CD spectrum, and unfolded cooperativity with guanidinium chloride. In contrast, the carboxyl-terminal fragment p2 was less compact than fragment p1, possessed only a weak far-UV and no detectable near-UV CD spectrum, and unfolded noncooperatively. The fragments assembled stoichiometrically to a complex with Kd = 0.2 microM, which was enzymically almost fully active. The rate of assembly was limited by a first-order process, probably the isomerization of the carboxyl-terminal fragment p2 to an assembly-competent structure. These results support a folding mechanism that comprises an intermediate with the first six beta alpha units folded in roughly native format and the last two beta alpha units partially unfolded. The similar behavior of the analogous fragments of the alpha subunit of tryptophan synthease supports the hypothesis that these two (beta alpha)8-barrel proteins have evolved from a common ancestor. |
| تدمد: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi00129a010 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e1af718e9d9abdd5273eeea007c56626 https://doi.org/10.1021/bi00129a010 |
| رقم الانضمام: | edsair.doi.dedup.....e1af718e9d9abdd5273eeea007c56626 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15204995 00062960 |
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| DOI: | 10.1021/bi00129a010 |