2enb: Difference between revisions
New page: left|200px<br /><applet load="2enb" size="450" color="white" frame="true" align="right" spinBox="true" caption="2enb, resolution 2.05Å" /> '''CRYSTAL STRUCTURES O... |
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[[Image:2enb.gif|left|200px]]<br /><applet load="2enb" size=" | [[Image:2enb.gif|left|200px]]<br /><applet load="2enb" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2enb, resolution 2.05Å" /> | caption="2enb, resolution 2.05Å" /> | ||
'''CRYSTAL STRUCTURES OF THE BINARY CA2+ AND PDTP COMPLEXES AND THE TERNARY COMPLEX OF THE ASP 21->GLU MUTANT OF STAPHYLOCOCCAL NUCLEASE. IMPLICATIONS FOR CATALYSIS AND LIGAND BINDING'''<br /> | '''CRYSTAL STRUCTURES OF THE BINARY CA2+ AND PDTP COMPLEXES AND THE TERNARY COMPLEX OF THE ASP 21->GLU MUTANT OF STAPHYLOCOCCAL NUCLEASE. IMPLICATIONS FOR CATALYSIS AND LIGAND BINDING'''<br /> | ||
==Overview== | ==Overview== | ||
The crystal structure of the Asp21-->Glu mutant (D21E) of staphylococcal | The crystal structure of the Asp21-->Glu mutant (D21E) of staphylococcal nuclease (SNase) has been determined in three different complex forms. The structure of the D21E ternary complex in which D21E is bound to both Ca2+ and the transition-state analogue, thymidine 3',5'-diphosphate (pdTp), was determined to 1.95-A resolution. The structures of both binary complexes, D21E bound either to Ca2+ or pdTp, were determined to 2.15- and 2.05-A resolution, respectively. In the ternary structure, we find a 1.5-A movement of the Ca2+ in the active site, evidence of bidentate coordination of Ca2+ by Glu21 and inner-sphere coordination of the Ca2+ by Glu43. Comparison of the D21E binary structures with the ternary model shows large movements of active site side chains expected to play a direct role in catalysis. Glu43 moves in the binary nucleotide complex, whereas Arg35 is oriented differently in the binary metal complex. From these changes, we seek to explain the basis for the 1500-fold decrease in Vmax of D21E relative to wild-type SNase (WT). Furthermore, we describe direct structural evidence which explains the cooperativity of Ca2+ and pdTp binding in the ternary complex relative to that of the binary complexes. | ||
==About this Structure== | ==About this Structure== | ||
2ENB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus] with THP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Micrococcal_nuclease Micrococcal nuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.31.1 3.1.31.1] Full crystallographic information is available from [http:// | 2ENB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus] with <scene name='pdbligand=THP:'>THP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Micrococcal_nuclease Micrococcal nuclease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.31.1 3.1.31.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ENB OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
[[Category: Gittis, A.]] | [[Category: Gittis, A.]] | ||
[[Category: Lattman, E | [[Category: Lattman, E E.]] | ||
[[Category: Libson, A.]] | [[Category: Libson, A.]] | ||
[[Category: THP]] | [[Category: THP]] | ||
[[Category: hydrolase(phosphoric diester)]] | [[Category: hydrolase(phosphoric diester)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:12:44 2008'' | ||
Revision as of 18:12, 21 February 2008
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CRYSTAL STRUCTURES OF THE BINARY CA2+ AND PDTP COMPLEXES AND THE TERNARY COMPLEX OF THE ASP 21->GLU MUTANT OF STAPHYLOCOCCAL NUCLEASE. IMPLICATIONS FOR CATALYSIS AND LIGAND BINDING
OverviewOverview
The crystal structure of the Asp21-->Glu mutant (D21E) of staphylococcal nuclease (SNase) has been determined in three different complex forms. The structure of the D21E ternary complex in which D21E is bound to both Ca2+ and the transition-state analogue, thymidine 3',5'-diphosphate (pdTp), was determined to 1.95-A resolution. The structures of both binary complexes, D21E bound either to Ca2+ or pdTp, were determined to 2.15- and 2.05-A resolution, respectively. In the ternary structure, we find a 1.5-A movement of the Ca2+ in the active site, evidence of bidentate coordination of Ca2+ by Glu21 and inner-sphere coordination of the Ca2+ by Glu43. Comparison of the D21E binary structures with the ternary model shows large movements of active site side chains expected to play a direct role in catalysis. Glu43 moves in the binary nucleotide complex, whereas Arg35 is oriented differently in the binary metal complex. From these changes, we seek to explain the basis for the 1500-fold decrease in Vmax of D21E relative to wild-type SNase (WT). Furthermore, we describe direct structural evidence which explains the cooperativity of Ca2+ and pdTp binding in the ternary complex relative to that of the binary complexes.
About this StructureAbout this Structure
2ENB is a Single protein structure of sequence from Staphylococcus aureus with as ligand. Active as Micrococcal nuclease, with EC number 3.1.31.1 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of the binary Ca2+ and pdTp complexes and the ternary complex of the Asp21-->Glu mutant of staphylococcal nuclease. Implications for catalysis and ligand binding., Libson AM, Gittis AG, Lattman EE, Biochemistry. 1994 Jul 5;33(26):8007-16. PMID:8025105
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