1sqc
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The crystal structure of squalene-hopene cyclase from Alicyclobacillus | + | The crystal structure of squalene-hopene cyclase from Alicyclobacillus acidocaldarius was determined at 2.9 angstrom resolution. The mechanism and sequence of this cyclase are closely related to those of 2,3-oxidosqualene cyclases that catalyze the cyclization step in cholesterol biosynthesis. The structure reveals a membrane protein with membrane-binding characteristics similar to those of prostaglandin-H2 synthase, the only other reported protein of this type. The active site of the enzyme is located in a large central cavity that is of suitable size to bind squalene in its required conformation and that is lined by aromatic residues. The structure supports a mechanism in which the acid starting the reaction by protonating a carbon-carbon double bond is an aspartate that is coupled to a histidine. Numerous surface alpha helices are connected by characteristic QW-motifs (Q is glutamine and W is tryptophan) that tighten the protein structure, possibly for absorbing the reaction energy without structural damage. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Alicyclobacillus acidocaldarius]] | [[Category: Alicyclobacillus acidocaldarius]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Schulz, G | + | [[Category: Schulz, G E.]] |
| - | [[Category: Wendt, K | + | [[Category: Wendt, K U.]] |
[[Category: LDA]] | [[Category: LDA]] | ||
[[Category: 29-ene) and diplopterol (hopane-22-ol)]] | [[Category: 29-ene) and diplopterol (hopane-22-ol)]] | ||
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[[Category: terpenoid metabolism]] | [[Category: terpenoid metabolism]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:04:06 2008'' |
Revision as of 13:04, 21 February 2008
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SQUALENE-HOPENE-CYCLASE FROM ALICYCLOBACILLUS ACIDOCALDARIUS
Overview
The crystal structure of squalene-hopene cyclase from Alicyclobacillus acidocaldarius was determined at 2.9 angstrom resolution. The mechanism and sequence of this cyclase are closely related to those of 2,3-oxidosqualene cyclases that catalyze the cyclization step in cholesterol biosynthesis. The structure reveals a membrane protein with membrane-binding characteristics similar to those of prostaglandin-H2 synthase, the only other reported protein of this type. The active site of the enzyme is located in a large central cavity that is of suitable size to bind squalene in its required conformation and that is lined by aromatic residues. The structure supports a mechanism in which the acid starting the reaction by protonating a carbon-carbon double bond is an aspartate that is coupled to a histidine. Numerous surface alpha helices are connected by characteristic QW-motifs (Q is glutamine and W is tryptophan) that tighten the protein structure, possibly for absorbing the reaction energy without structural damage.
About this Structure
1SQC is a Single protein structure of sequence from Alicyclobacillus acidocaldarius with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure and function of a squalene cyclase., Wendt KU, Poralla K, Schulz GE, Science. 1997 Sep 19;277(5333):1811-5. PMID:9295270
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