2o8v
From Proteopedia
(New page: 200px<br /><applet load="2o8v" size="450" color="white" frame="true" align="right" spinBox="true" caption="2o8v, resolution 3.000Å" /> '''PAPS reductase in a...) |
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| - | [[Image:2o8v.gif|left|200px]]<br /><applet load="2o8v" size=" | + | [[Image:2o8v.gif|left|200px]]<br /><applet load="2o8v" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2o8v, resolution 3.000Å" /> | caption="2o8v, resolution 3.000Å" /> | ||
'''PAPS reductase in a covalent complex with thioredoxin C35A'''<br /> | '''PAPS reductase in a covalent complex with thioredoxin C35A'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of Escherichia coli | + | The crystal structure of Escherichia coli 3'-phosphoadenosine-5'-phosphosulfate (PAPS) reductase in complex with E. coli thioredoxin 1 (Trx1) has been determined to 3.0 A resolution. The two proteins are covalently linked via a mixed disulfide that forms during nucleophilic attack of Trx's N-terminal cysteine on the Sgamma atom of the PAPS reductase S-sulfocysteine (E-Cys-Sgamma-SO3-), a central intermediate in the catalytic cycle. For the first time in a crystal structure, residues 235-244 in the PAPS reductase C-terminus are observed, depicting an array of interprotein salt bridges between Trx and the strictly conserved glutathione-like sequence, Glu238Cys239Gly240Leu241His242. The structure also reveals a Trx-binding surface adjacent to the active site cleft and regions of PAPS reductase associated with conformational change. Interaction at this site strategically positions Trx to bind the S-sulfated C-terminus and addresses the mechanism for requisite structural rearrangement of this domain. An apparent sulfite-binding pocket at the protein-protein interface explicitly orients the S-sulfocysteine Sgamma atom for nucleophilic attack in a subsequent step. Taken together, the structure of PAPS reductase in complex with Trx highlights the large structural rearrangement required to accomplish sulfonucleotide reduction and suggests a role for Trx in catalysis beyond the paradigm of disulfide reduction. |
==About this Structure== | ==About this Structure== | ||
| - | 2O8V is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. 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:// | + | 2O8V is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. 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=2O8V OCA]. |
==Reference== | ==Reference== | ||
| - | 3'-Phosphoadenosine-5'-phosphosulfate | + | 3'-Phosphoadenosine-5'-phosphosulfate reductase in complex with thioredoxin: a structural snapshot in the catalytic cycle., Chartron J, Shiau C, Stout CD, Carroll KS, Biochemistry. 2007 Apr 3;46(13):3942-51. Epub 2007 Mar 13. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17352498 17352498] |
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Phosphoadenylyl-sulfate reductase (thioredoxin)]] | [[Category: Phosphoadenylyl-sulfate reductase (thioredoxin)]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Carroll, K | + | [[Category: Carroll, K S.]] |
[[Category: Chartron, J.]] | [[Category: Chartron, J.]] | ||
[[Category: Shiau, C.]] | [[Category: Shiau, C.]] | ||
| - | [[Category: Stout, C | + | [[Category: Stout, C D.]] |
[[Category: disulfide crosslinked complex]] | [[Category: disulfide crosslinked complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:15:45 2008'' |
Revision as of 16:15, 21 February 2008
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PAPS reductase in a covalent complex with thioredoxin C35A
Overview
The crystal structure of Escherichia coli 3'-phosphoadenosine-5'-phosphosulfate (PAPS) reductase in complex with E. coli thioredoxin 1 (Trx1) has been determined to 3.0 A resolution. The two proteins are covalently linked via a mixed disulfide that forms during nucleophilic attack of Trx's N-terminal cysteine on the Sgamma atom of the PAPS reductase S-sulfocysteine (E-Cys-Sgamma-SO3-), a central intermediate in the catalytic cycle. For the first time in a crystal structure, residues 235-244 in the PAPS reductase C-terminus are observed, depicting an array of interprotein salt bridges between Trx and the strictly conserved glutathione-like sequence, Glu238Cys239Gly240Leu241His242. The structure also reveals a Trx-binding surface adjacent to the active site cleft and regions of PAPS reductase associated with conformational change. Interaction at this site strategically positions Trx to bind the S-sulfated C-terminus and addresses the mechanism for requisite structural rearrangement of this domain. An apparent sulfite-binding pocket at the protein-protein interface explicitly orients the S-sulfocysteine Sgamma atom for nucleophilic attack in a subsequent step. Taken together, the structure of PAPS reductase in complex with Trx highlights the large structural rearrangement required to accomplish sulfonucleotide reduction and suggests a role for Trx in catalysis beyond the paradigm of disulfide reduction.
About this Structure
2O8V is a Protein complex structure of sequences from Escherichia coli. Active as Phosphoadenylyl-sulfate reductase (thioredoxin), with EC number 1.8.4.8 Full crystallographic information is available from OCA.
Reference
3'-Phosphoadenosine-5'-phosphosulfate reductase in complex with thioredoxin: a structural snapshot in the catalytic cycle., Chartron J, Shiau C, Stout CD, Carroll KS, Biochemistry. 2007 Apr 3;46(13):3942-51. Epub 2007 Mar 13. PMID:17352498
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