1t2h
From Proteopedia
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| - | [[Image:1t2h.gif|left|200px]] | + | [[Image:1t2h.gif|left|200px]] |
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| - | '''Y81W mutant of RNase Sa from Streptomyces aureofaciens''' | + | {{Structure |
| + | |PDB= 1t2h |SIZE=350|CAPTION= <scene name='initialview01'>1t2h</scene>, resolution 1.00Å | ||
| + | |SITE= | ||
| + | |LIGAND= <scene name='pdbligand=SO4:SULFATE ION'>SO4</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/Ribonuclease_T(1) Ribonuclease T(1)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.27.3 3.1.27.3] | ||
| + | |GENE= U39467 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1894 Streptomyces aureofaciens]) | ||
| + | }} | ||
| + | |||
| + | '''Y81W mutant of RNase Sa from Streptomyces aureofaciens''' | ||
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==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1T2H is a [ | + | 1T2H is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_aureofaciens Streptomyces aureofaciens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T2H OCA]. |
==Reference== | ==Reference== | ||
| - | Contribution of single tryptophan residues to the fluorescence and stability of ribonuclease Sa., Alston RW, Urbanikova L, Sevcik J, Lasagna M, Reinhart GD, Scholtz JM, Pace CN, Biophys J. 2004 Dec;87(6):4036-47. Epub 2004 Sep 17. PMID:[http:// | + | Contribution of single tryptophan residues to the fluorescence and stability of ribonuclease Sa., Alston RW, Urbanikova L, Sevcik J, Lasagna M, Reinhart GD, Scholtz JM, Pace CN, Biophys J. 2004 Dec;87(6):4036-47. Epub 2004 Sep 17. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15377518 15377518] |
[[Category: Ribonuclease T(1)]] | [[Category: Ribonuclease T(1)]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: ribonuclease]] | [[Category: ribonuclease]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 14:12:50 2008'' |
Revision as of 12:12, 20 March 2008
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| , resolution 1.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | U39467 (Streptomyces aureofaciens) | ||||||
| Activity: | Ribonuclease T(1), with EC number 3.1.27.3 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Y81W mutant of RNase Sa from Streptomyces aureofaciens
Overview
Ribonuclease Sa (RNase Sa) contains no tryptophan (Trp) residues. We have added single Trp residues to RNase Sa at sites where Trp is found in four other microbial ribonucleases, yielding the following variants of RNase Sa: Y52W, Y55W, T76W, and Y81W. We have determined crystal structures of T76W and Y81W at 1.1 and 1.0 A resolution, respectively. We have studied the fluorescence properties and stabilities of the four variants and compared them to wild-type RNase Sa and the other ribonucleases on which they were based. Our results should help others in selecting sites for adding Trp residues to proteins. The most interesting findings are: 1), Y52W is 2.9 kcal/mol less stable than RNase Sa and the fluorescence intensity emission maximum is blue-shifted to 309 nm. Only a Trp in azurin is blue-shifted to a greater extent (308 nm). This blue shift is considerably greater than observed for Trp71 in barnase, the Trp on which Y52W is based. 2), Y55W is 2.1 kcal/mol less stable than RNase Sa and the tryptophan fluorescence is almost completely quenched. In contrast, Trp59 in RNase T1, on which Y55W is based, has a 10-fold greater fluorescence emission intensity. 3), T76W is 0.7 kcal/mol more stable than RNase Sa, indicating that the Trp side chain has more favorable interactions with the protein than the threonine side chain. The fluorescence properties of folded Y76W are similar to those of the unfolded protein, showing that the tryptophan side chain in the folded protein is largely exposed to solvent. This is confirmed by the crystal structure of the T76W which shows that the side chain of the Trp is only approximately 7% buried. 4), Y81W is 0.4 kcal/mol less stable than RNase Sa. Based on the crystal structure of Y81W, the side chain of the Trp is 87% buried. Although all of the Trp side chains in the variants contribute to the unusual positive circular dichroism band observed near 235 nm for RNase Sa, the contribution is greatest for Y81W.
About this Structure
1T2H is a Single protein structure of sequence from Streptomyces aureofaciens. Full crystallographic information is available from OCA.
Reference
Contribution of single tryptophan residues to the fluorescence and stability of ribonuclease Sa., Alston RW, Urbanikova L, Sevcik J, Lasagna M, Reinhart GD, Scholtz JM, Pace CN, Biophys J. 2004 Dec;87(6):4036-47. Epub 2004 Sep 17. PMID:15377518
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