1dbi
From Proteopedia
(New page: 200px<br /><applet load="1dbi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1dbi, resolution 1.8Å" /> '''CRYSTAL STRUCTURE OF ...) |
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| - | [[Image:1dbi.gif|left|200px]]<br /><applet load="1dbi" size=" | + | [[Image:1dbi.gif|left|200px]]<br /><applet load="1dbi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1dbi, resolution 1.8Å" /> | caption="1dbi, resolution 1.8Å" /> | ||
'''CRYSTAL STRUCTURE OF A THERMOSTABLE SERINE PROTEASE'''<br /> | '''CRYSTAL STRUCTURE OF A THERMOSTABLE SERINE PROTEASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Proteins of the subtilisin superfamily (subtilases) are widely distributed | + | Proteins of the subtilisin superfamily (subtilases) are widely distributed through many living species, where they perform a variety of processing functions. They are also used extensively in industry. In many of these enzymes, bound calcium ions play a key role in protecting against autolysis and thermal denaturation. We have determined the crystal structure of a highly thermostable protease from Bacillus sp. Ak.1 that is strongly stabilized by calcium. The crystal structure, determined at 1.8 A resolution (R=0. 182, Rfree=0.247), reveals the presence of four bound cations, three Ca(2+) and one Na(+). Two of the Ca(2+) binding sites, Ca-1 and Ca-2, correspond to sites also found in thermitase and the mesophilic subtilisins. The third calcium ion, however, is at a novel site that is created by two key amino acid substitutions near Ca-1, and has not been observed in any other subtilase. This site, acting cooperatively with Ca-1, appears to give substantially enhanced thermostability, compared with thermitase. Comparisons with the mesophilic subtilisins also point to the importance of aromatic clusters, reduced hydrophobic surface and constrained N and C termini in enhancing the thermostability of thermitase and Ak.1 protease. The Ak.1 protease also contains an unusual Cys-X-Cys disulfide bridge that modifies the active site cleft geometry. |
==About this Structure== | ==About this Structure== | ||
| - | 1DBI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.] with CA and NA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1DBI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_sp. Bacillus sp.] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DBI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bacillus sp.]] | [[Category: Bacillus sp.]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Baker, E | + | [[Category: Baker, E N.]] |
| - | [[Category: Baker, H | + | [[Category: Baker, H M.]] |
| - | [[Category: Daniel, R | + | [[Category: Daniel, R M.]] |
| - | [[Category: Smith, C | + | [[Category: Smith, C A.]] |
| - | [[Category: Toogood, H | + | [[Category: Toogood, H S.]] |
[[Category: CA]] | [[Category: CA]] | ||
[[Category: NA]] | [[Category: NA]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:14:56 2008'' |
Revision as of 10:14, 21 February 2008
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CRYSTAL STRUCTURE OF A THERMOSTABLE SERINE PROTEASE
Overview
Proteins of the subtilisin superfamily (subtilases) are widely distributed through many living species, where they perform a variety of processing functions. They are also used extensively in industry. In many of these enzymes, bound calcium ions play a key role in protecting against autolysis and thermal denaturation. We have determined the crystal structure of a highly thermostable protease from Bacillus sp. Ak.1 that is strongly stabilized by calcium. The crystal structure, determined at 1.8 A resolution (R=0. 182, Rfree=0.247), reveals the presence of four bound cations, three Ca(2+) and one Na(+). Two of the Ca(2+) binding sites, Ca-1 and Ca-2, correspond to sites also found in thermitase and the mesophilic subtilisins. The third calcium ion, however, is at a novel site that is created by two key amino acid substitutions near Ca-1, and has not been observed in any other subtilase. This site, acting cooperatively with Ca-1, appears to give substantially enhanced thermostability, compared with thermitase. Comparisons with the mesophilic subtilisins also point to the importance of aromatic clusters, reduced hydrophobic surface and constrained N and C termini in enhancing the thermostability of thermitase and Ak.1 protease. The Ak.1 protease also contains an unusual Cys-X-Cys disulfide bridge that modifies the active site cleft geometry.
About this Structure
1DBI is a Single protein structure of sequence from Bacillus sp. with and as ligands. Full crystallographic information is available from OCA.
Reference
Calcium-mediated thermostability in the subtilisin superfamily: the crystal structure of Bacillus Ak.1 protease at 1.8 A resolution., Smith CA, Toogood HS, Baker HM, Daniel RM, Baker EN, J Mol Biol. 1999 Dec 10;294(4):1027-40. PMID:10588904
Page seeded by OCA on Thu Feb 21 12:14:56 2008
Categories: Bacillus sp. | Single protein | Baker, E N. | Baker, H M. | Daniel, R M. | Smith, C A. | Toogood, H S. | CA | NA | Hydrolase
