1ilo: Difference between revisions

[[Image:1ilo.gif|left|200px]]<br /><applet load="1ilo" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1ILO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanothermobacter_thermautotrophicus Methanothermobacter thermautotrophicus]. Active as [http://en.wikipedia.org/wiki/Phosphoadenylyl-sulfate_reductase_(thioredoxin) Phosphoadenylyl-sulfate reductase (thioredoxin)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.4.8 1.8.4.8] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ILO OCA].  

[[Category: NESG, Northeast Structural Genomics Consortium.]]

[[Category: Slupsky, C M.]]

[[Category: Sykes, B D.]]

[[Category: Wishart, D S.]]

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