1oas
From Proteopedia
(New page: 200px<br /><applet load="1oas" size="450" color="white" frame="true" align="right" spinBox="true" caption="1oas, resolution 2.200Å" /> '''O-ACETYLSERINE SULF...) |
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| - | [[Image:1oas.gif|left|200px]]<br /><applet load="1oas" size=" | + | [[Image:1oas.gif|left|200px]]<br /><applet load="1oas" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1oas, resolution 2.200Å" /> | caption="1oas, resolution 2.200Å" /> | ||
'''O-ACETYLSERINE SULFHYDRYLASE FROM SALMONELLA TYPHIMURIUM'''<br /> | '''O-ACETYLSERINE SULFHYDRYLASE FROM SALMONELLA TYPHIMURIUM'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The last step in cysteine biosynthesis in enteric bacteria is catalyzed by | + | The last step in cysteine biosynthesis in enteric bacteria is catalyzed by the pyridoxal 5'-phosphate-dependent enzyme O-acetylserine sulfhydrylase. Here we report the crystal structure at 2.2 A resolution of the A-isozyme of O-acetylserine sulfhydrylase isolated from Salmonella typhimurium. O-acetylserine sulfhydrylase shares the same fold with tryptophan synthase-beta from Salmonella typhimurium but the sequence identity level is below 20%. There are some major structural differences: the loops providing the interface to the alpha-subunit in tryptophan synthase-beta and two surface helices of tryptophan synthase-beta are missing in O-acetylserine sulfhydrylase. The hydrophobic channel for indole transport from the alpha to the beta active site of tryptophan synthase-beta is, not unexpectedly, also absent in O-acetylserine sulfhydrylase. The dimer interface, on the other hand, is more or less conserved in the two enzymes. The active site cleft of O-acetylserine sulfhydrylase is wider and therefore more exposed to the solvent. A possible binding site for the substrate O-acetylserine is discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 1OAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with PLP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Cysteine_synthase Cysteine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.47 2.5.1.47] Full crystallographic information is available from [http:// | + | 1OAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salmonella_typhimurium Salmonella typhimurium] with <scene name='pdbligand=PLP:'>PLP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Cysteine_synthase Cysteine synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.47 2.5.1.47] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OAS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Burkhard, P.]] | [[Category: Burkhard, P.]] | ||
| - | [[Category: Cook, P | + | [[Category: Cook, P F.]] |
[[Category: Hohenester, E.]] | [[Category: Hohenester, E.]] | ||
| - | [[Category: Jansonius, J | + | [[Category: Jansonius, J N.]] |
| - | [[Category: Rao, G | + | [[Category: Rao, G S.J.]] |
| - | [[Category: Schnackerz, K | + | [[Category: Schnackerz, K D.]] |
[[Category: PLP]] | [[Category: PLP]] | ||
[[Category: beta replacement enzyme]] | [[Category: beta replacement enzyme]] | ||
| Line 26: | Line 26: | ||
[[Category: plp dependent enzyme]] | [[Category: plp dependent enzyme]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:15:28 2008'' |
Revision as of 12:15, 21 February 2008
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O-ACETYLSERINE SULFHYDRYLASE FROM SALMONELLA TYPHIMURIUM
Overview
The last step in cysteine biosynthesis in enteric bacteria is catalyzed by the pyridoxal 5'-phosphate-dependent enzyme O-acetylserine sulfhydrylase. Here we report the crystal structure at 2.2 A resolution of the A-isozyme of O-acetylserine sulfhydrylase isolated from Salmonella typhimurium. O-acetylserine sulfhydrylase shares the same fold with tryptophan synthase-beta from Salmonella typhimurium but the sequence identity level is below 20%. There are some major structural differences: the loops providing the interface to the alpha-subunit in tryptophan synthase-beta and two surface helices of tryptophan synthase-beta are missing in O-acetylserine sulfhydrylase. The hydrophobic channel for indole transport from the alpha to the beta active site of tryptophan synthase-beta is, not unexpectedly, also absent in O-acetylserine sulfhydrylase. The dimer interface, on the other hand, is more or less conserved in the two enzymes. The active site cleft of O-acetylserine sulfhydrylase is wider and therefore more exposed to the solvent. A possible binding site for the substrate O-acetylserine is discussed.
About this Structure
1OAS is a Single protein structure of sequence from Salmonella typhimurium with as ligand. Active as Cysteine synthase, with EC number 2.5.1.47 Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of O-acetylserine sulfhydrylase from Salmonella typhimurium., Burkhard P, Rao GS, Hohenester E, Schnackerz KD, Cook PF, Jansonius JN, J Mol Biol. 1998;283(1):121-33. PMID:9761678
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