The adaptability of Escherichia coli thioredoxin to non-conservative amino acid substitutions.
Abstract
The adaptability of Escherichia coli thioredoxin to the substitution of a series of non-natural amino acids has been investigated. Different thiosulfonated alkyl groups were inserted into the hydrophobic core of the protein in position 78 via disulfide bonding with a buried cysteine residue as previously described (Wynn R, Richards FM. 1993. Unnatural amino acid packing mutants of Escherichia coli thioredoxin produced by combined mutagenesis/chemical modification techniques. Protein Sci 2:395-403). The side chains added to the cysteine included methyl, ethyl, n-propyl, n-butyl, n-pentyl, and cyclo-pentyl derivatives. The side chains appear to exploit the presence of the large cavities to incorporate these variant forms, enabling the protein to fold and have some activity. Solution structural and kinetic data suggested that these substitutions had little effect on the overall fold of the protein. Thermodynamic data revealed that the entropic effect of restricting the side chains in the folded protein has an effect on the stability. The variant forms of thioredoxin have different propensities to form dimers despite the limited structural perturbations. Molecular modeling studies allow the conformation of the side chains to be assessed. Study holds ProTherm entries: 9392, 9393, 9394, 9395, 9396, 9397, 9398, 9399, 9400, 9401, 9402, 9403, 9404, 9405, 9406, 9407, 9408, 9409, 9410, 9411, 9412 Extra Details: calorimetry; cysteine modification; differential scanning; kinetics; protein folding; thermodynamics: thioredoxin; unnatural amino acids
Submission Details
ID: kHz5G3mZ3
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:38 p.m.
Version: 1
Publication Details
O'Brien R;Wynn R;Driscoll PC;Davis B;Plaxco KW;Sturtevant JM;Ladbury JE,Protein Sci. (1997) The adaptability of Escherichia coli thioredoxin to non-conservative amino acid substitutions. PMID:9194193Additional Information
Study Summary
Structure view and single mutant data analysis
Study data
| Colors: | D | E | R | H | K | S | T | N | Q | A | V | I | L | M | F | Y | W | C | G | P |
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Data Distribution
Studies with similar sequences (approximate matches)
Correlation with other assays (exact sequence matches)
Relevant PDB Entries
| Structure ID | Release Date | Resolution | Structure Title |
|---|---|---|---|
| 5IKN | 2016-03-03T00:00:00+0000 | 4.8 | Crystal Structure of the T7 Replisome in the Absence of DNA |
| 3DXB | 2008-07-24T00:00:00+0000 | 2.2 | Structure of the UHM domain of Puf60 fused to thioredoxin |
| 5E4W | 2015-10-07T00:00:00+0000 | 2.8 | Crystal structure of cpSRP43 chromodomains 2 and 3 in complex with the Alb3 tail |
| 1TKD | 2004-06-08T00:00:00+0000 | 2.49 | T7 DNA polymerase ternary complex with 8 oxo guanosine and dCMP at the elongation site |
| 1TK0 | 2004-06-07T00:00:00+0000 | 2.3 | T7 DNA polymerase ternary complex with 8 oxo guanosine and ddCTP at the insertion site |
| 2EIQ | 2007-03-13T00:00:00+0000 | 1.9 | Design of Disulfide-linked Thioredoxin Dimers and Multimers Through Analysis of Crystal Contacts |
| 2AJQ | 2005-08-02T00:00:00+0000 | 2.6 | Structure of replicative DNA polymerase provides insigts into the mechanisms for processivity, frameshifting and editing |
| 1ZCP | 2005-04-12T00:00:00+0000 | 2.3 | Crystal Structure of a catalytic site mutant E. coli TrxA (CACA) |
| 2EIO | 2007-03-13T00:00:00+0000 | 2.6 | Design of Disulfide-linked Thioredoxin Dimers and Multimers Through Analysis of Crystal Contacts |
| 1X9M | 2004-08-23T00:00:00+0000 | 2.1 | T7 DNA polymerase in complex with an N-2-acetylaminofluorene-adducted DNA |