Sandbox reserved 919: Difference between revisions
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<StructureSection load='3DNM' size='350' frame='true' align='right' caption='Hormone-Sensitive Lipase from [[3dnm]]' scene='58/580297/3dnm_cartoon/2' > | <StructureSection load='3DNM' size='350' frame='true' align='right' caption='Hormone-Sensitive Lipase from [[3dnm]]' scene='58/580297/3dnm_cartoon/2' > | ||
<scene name='58/580297/3dnm_cartoon_dotsribbon/1'>Hormone-sensitive lipases</scene> are generally well-conserved across domains, including prokaryotes, showing 29, 26, and 22% residue overlap in [http://en.wikipedia.org/wiki/Alicyclobacillus ''Alicyclobacillus acidocaldarius''], [http://en.wikipedia.org/wiki/Archaeoglobus ''Archaeoglobus fulgidus''], and [http://en.wikipedia.org/wiki/Bacillus_subtilis ''Bacillus subtilis''], respectively. <ref name="Nam">PMID:19089974</ref> HSL is composed of two main structural domains, consisting of a slightly variable N-terminus (shown in blue in the <scene name='58/580297/3dnm_cartoon/3'>default view</scene>) that is thought to contribute to numerous factors including activity, specificity, regioselectivity, thermophilicity, and thermostability. <ref name="Nam">PMID:19089974</ref> The second | <scene name='58/580297/3dnm_cartoon_dotsribbon/1'>Hormone-sensitive lipases</scene> are generally well-conserved across domains, including prokaryotes, showing 29, 26, and 22% residue overlap in [http://en.wikipedia.org/wiki/Alicyclobacillus ''Alicyclobacillus acidocaldarius''], [http://en.wikipedia.org/wiki/Archaeoglobus ''Archaeoglobus fulgidus''], and [http://en.wikipedia.org/wiki/Bacillus_subtilis ''Bacillus subtilis''], respectively. <ref name="Nam">PMID:19089974</ref> HSL is composed of two main structural domains, consisting of a slightly variable N-terminus (shown in blue in the <scene name='58/580297/3dnm_cartoon/3'>default view</scene>) that is thought to contribute to numerous factors including activity, specificity, regioselectivity, thermophilicity, and thermostability. <ref name="Nam">PMID:19089974</ref> Research speculates that the N-terminal domain, consisting of about 300 residues, mediates protein-protein interactions, and possibly subsequent lipid binding. <ref name= "Yeaman">PMID:14725507</ref> The second domain of HSL is the C-terminal catalytic domain (colors other than blue), which contains serine residue phosphorylation sites as well as the [http://en.wikipedia.org/wiki/Catalytic_triad catalytic triad], viewed <scene name='58/580297/3dnm_triad_zoomedout/1'>here</scene>, a charge relay network that is characteristic of many hydrolases. <ref name= "Yeaman">PMID:14725507</ref> With respect to sequence conservation across species, it has been shown that the catalytic domain, including the triad, is conserved across domains, but the domain containing the N-terminus shows little conservation. <ref name="Nam">PMID:19089974</ref> Size-exclusion chromatography studies have shown that HSL has a ligand pocket that is approximately 16Å deep, suggesting that HSL primarily hydrolyzes shorter chained molecules. <ref name="Nam">PMID:19089974</ref> | ||
The catalytic triad <scene name='58/580297/3dnm_triad_zoomedin/1'>situates itself</scene> toward the middle of HSL. The catalytic triad is composed of residues <scene name='58/580297/3dnm_ligandsite_triad_chains/4'>Ser157, Glu251, and His281</scene>. The Ser157 residue sits at a site deemed the "nucleophilic elbow," that models an approximate torsion of Φ = 60° and Ψ =-120°. This nucleophilic elbow is stabilized by a hydrogen bond between the proximal nitrogen and oxygen atoms of His281 and Glu251, respectively. This model also shows the strong nucleophilic character of Ser157, portraying the covalent binding to <scene name='58/580297/3dnm_ligandsite_triad_chains/3'>β-mercaptoethanol</scene>. Return to default view, <scene name='58/580297/3dnm_cartoon/3'>here</scene>. | The catalytic triad <scene name='58/580297/3dnm_triad_zoomedin/1'>situates itself</scene> toward the middle of HSL. The catalytic triad is composed of residues <scene name='58/580297/3dnm_ligandsite_triad_chains/4'>Ser157, Glu251, and His281</scene>. The Ser157 residue sits at a site deemed the "nucleophilic elbow," that models an approximate torsion of Φ = 60° and Ψ =-120°. This nucleophilic elbow is stabilized by a hydrogen bond between the proximal nitrogen and oxygen atoms of His281 and Glu251, respectively. This model also shows the strong nucleophilic character of Ser157, portraying the covalent binding to <scene name='58/580297/3dnm_ligandsite_triad_chains/3'>β-mercaptoethanol</scene>. Return to default view, <scene name='58/580297/3dnm_cartoon/3'>here</scene>. | ||