1box: Difference between revisions
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[[Image:1box.gif|left|200px]] | [[Image:1box.gif|left|200px]] | ||
'''N39S MUTANT OF RNASE SA FROM STREPTOMYCES AUREOFACIENS''' | {{Structure | ||
|PDB= 1box |SIZE=350|CAPTION= <scene name='initialview01'>1box</scene>, resolution 1.6Å | |||
|SITE= | |||
|LIGAND= | |||
|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]) | |||
}} | |||
'''N39S MUTANT OF RNASE SA FROM STREPTOMYCES AUREOFACIENS''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1BOX is a [ | 1BOX 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=1BOX OCA]. | ||
==Reference== | ==Reference== | ||
Contribution of a conserved asparagine to the conformational stability of ribonucleases Sa, Ba, and T1., Hebert EJ, Giletto A, Sevcik J, Urbanikova L, Wilson KS, Dauter Z, Pace CN, Biochemistry. 1998 Nov 17;37(46):16192-200. PMID:[http:// | Contribution of a conserved asparagine to the conformational stability of ribonucleases Sa, Ba, and T1., Hebert EJ, Giletto A, Sevcik J, Urbanikova L, Wilson KS, Dauter Z, Pace CN, Biochemistry. 1998 Nov 17;37(46):16192-200. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9819211 9819211] | ||
[[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 10:13:57 2008'' | ||
Revision as of 11:13, 20 March 2008
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| , resolution 1.6Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | U39467 (Streptomyces aureofaciens) | ||||||
| Activity: | Ribonuclease T(1), with EC number 3.1.27.3 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
N39S MUTANT OF RNASE SA FROM STREPTOMYCES AUREOFACIENS
OverviewOverview
The contribution of hydrogen bonding by peptide groups to the conformational stability of globular proteins was studied. One of the conserved residues in the microbial ribonuclease (RNase) family is an asparagine at position 39 in RNase Sa, 44 in RNase T1, and 58 in RNase Ba (barnase). The amide group of this asparagine is buried and forms two similar intramolecular hydrogen bonds with a neighboring peptide group to anchor a loop on the surface of all three proteins. Thus, it is a good model for the hydrogen bonding of peptide groups. When the conserved asparagine is replaced with alanine, the decrease in the stability of the mutant proteins is 2.2 (Sa), 1.8 (T1), and 2.7 (Ba) kcal/mol. When the conserved asparagine is replaced by aspartate, the stability of the mutant proteins decreases by 1.5 and 1.8 kcal/mol for RNases Sa and T1, respectively, but increases by 0.5 kcal/mol for RNase Ba. When the conserved asparagine was replaced by serine, the stability of the mutant proteins was decreased by 2.3 and 1.7 kcal/mol for RNases Sa and T1, respectively. The structure of the Asn 39 --> Ser mutant of RNase Sa was determined at 1.7 A resolution. There is a significant conformational change near the site of the mutation: (1) the side chain of Ser 39 is oriented differently than that of Asn 39 and forms hydrogen bonds with two conserved water molecules; (2) the peptide bond of Ser 42 changes conformation in the mutant so that the side chain forms three new intramolecular hydrogen bonds with the backbone to replace three hydrogen bonds to water molecules present in the wild-type structure; and (3) the loss of the anchoring hydrogen bonds makes the surface loop more flexible in the mutant than it is in wild-type RNase Sa. The results show that burial and hydrogen bonding of the conserved asparagine make a large contribution to microbial RNase stability and emphasize the importance of structural information in interpreting stability studies of mutant proteins.
About this StructureAbout this Structure
1BOX is a Single protein structure of sequence from Streptomyces aureofaciens. Full crystallographic information is available from OCA.
ReferenceReference
Contribution of a conserved asparagine to the conformational stability of ribonucleases Sa, Ba, and T1., Hebert EJ, Giletto A, Sevcik J, Urbanikova L, Wilson KS, Dauter Z, Pace CN, Biochemistry. 1998 Nov 17;37(46):16192-200. PMID:9819211
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