|Biochemistry (2002) 41(15):4760-70|
|Northeast Structural Genomics Consortium|
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As part of a high-throughput, structural proteomic project we have used NMR spectroscopy to determine the solution structure and ascertain the function of a previously unknown, conserved protein (MtH895) from the thermophilic archeon Methanobacterium thermoautotrophicum. ...
Our findings indicate that MtH895 contains a central four-stranded beta-sheet core surrounded by two helices on one side and a third on the other. It has an overall fold superficially similar to that of a glutaredoxin. However, detailed analysis of its three-dimensional structure along with molecular docking simulations of its interaction with T7 DNA polymerase (a thioredoxin-specific substrate) and comparisons with other known members of the thioredoxin/glutaredoxin family of proteins strongly suggest that MtH895 is more akin to a thioredoxin. Furthermore, measurement of the pK(a) values of its active site thiols along with direct measurements of the thioredoxin/glutaredoxin activity has confirmed that MtH895 is, indeed, a thioredoxin and exhibits no glutaredoxin activity. We have also identified a group of previously unknown proteins from several other archaebacteria that have significant (34-44%) sequence identity with MtH895. These proteins have unusual active site -CXXC- motifs not found in any known thioredoxin or glutaredoxin. On the basis of the results presented here, we predict that these small proteins are all members of a new class of truncated thioredoxins.
|metabolism chemistry |
|Binding Sites Amino Acid Sequence Conserved Sequence Models, Molecular Molecular Sequence Data Sequence Alignment Protein Conformation Methanobacterium Solutions Magnetic Resonance Spectroscopy Thioredoxins Thermodynamics DNA-Directed DNA Polymerase |
|22 (Last update: 05/23/2018 9:16:34pm)|
|Biochemistry. 2002 Apr 16;41(15):4760-70.|