| http://purl.uniprot.org/citations/17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#type | http://purl.uniprot.org/core/Journal_Citation |
| http://purl.uniprot.org/citations/17661444 | http://www.w3.org/2000/01/rdf-schema#comment | "High-molecular weight thioredoxin reductases (TRs) catalyze the reduction of the redox-active disulfide bond of thioredoxin, but an important difference in the TR family is the sequence of the C-terminal redox-active tetrapeptide that interacts directly with thioredoxin, especially the presence or absence of a selenocysteine (Sec) residue in this tetrapeptide. In this study, we have employed protein engineering techniques to investigate the C-terminal redox-active tetrapeptides of three different TRs: mouse mitochondrial TR (mTR3), Drosophila melanogaster TR (DmTR), and the mitochondrial TR from Caenorhabditis elegans (CeTR2), which have C-terminal tetrapeptide sequences of Gly-Cys-Sec-Gly, Ser-Cys-Cys-Ser, and Gly-Cys-Cys-Gly, respectively. Three different types of mutations and chemical modifications were performed in this study: insertion of alanine residues between the cysteine residues of the Cys-Cys or Cys-Sec dyads, modification of the charge at the C-terminus, and altering the position of the Sec residue in the mammalian enzyme. The results show that mTR3 is quite accommodating to insertion of alanine residues into the Cys-Sec dyad, with only a 4-6-fold drop in catalytic activity. In contrast, the activity of both DmTR and CeTR2 was reduced 100-300-fold when alanine residues were inserted into the Cys-Cys dyad. We have tested the importance of a salt bridge between the C-terminus and a basic residue that was proposed for orienting the Cys-Sec dyad of mTR3 for proper catalytic position by changing the C-terminal carboxylate to a carboxamide. The result is an enzyme with twice the activity as the wild-type mammalian enzyme. A similar result was achieved when the C-terminal carboxylate of DmTR was converted to a hydroxamic acid or a thiocarboxylate. Last, reversing the positions of the Cys and Sec residues in the catalytic dyad resulted in a 100-fold loss of catalytic activity. Taken together, the results support our previous model of Sec as the leaving group during reduction of the C-terminus during the catalytic cycle."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.org/dc/terms/identifier | "doi:10.1021/bi7004812"xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/author | "Lacey B.M."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/author | "Eckenroth B.E."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/author | "Hondal R.J."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/author | "Lothrop A.P."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/author | "Harris K.M."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/date | "2007"xsd:gYear |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/name | "Biochemistry"xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/pages | "9472-9483"xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/title | "Investigation of the C-terminal redox center of high-Mr thioredoxin reductase by protein engineering and semisynthesis."xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://purl.uniprot.org/core/volume | "46"xsd:string |
| http://purl.uniprot.org/citations/17661444 | http://www.w3.org/2004/02/skos/core#exactMatch | http://purl.uniprot.org/pubmed/17661444 |
| http://purl.uniprot.org/citations/17661444 | http://xmlns.com/foaf/0.1/primaryTopicOf | https://pubmed.ncbi.nlm.nih.gov/17661444 |
| http://purl.uniprot.org/uniprot/P30635#attribution-D7A3CC9C57D1843E3CB23F919ED44C5F | http://purl.uniprot.org/core/source | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0U1RPC6-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_D3Z0K8-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0M3HEP9-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0M3HEQ0-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0U1RPS1-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0U1RPV8-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0U1RPY5-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A0U1RQA4-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |
| http://purl.uniprot.org/uniprot/#_A0A6H2EFX8-mappedCitation-17661444 | http://www.w3.org/1999/02/22-rdf-syntax-ns#object | http://purl.uniprot.org/citations/17661444 |