1b6b
From Proteopedia
(New page: 200px<br /><applet load="1b6b" size="450" color="white" frame="true" align="right" spinBox="true" caption="1b6b, resolution 2.5Å" /> '''MELATONIN BIOSYNTHESI...) |
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| - | [[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size=" | + | [[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1b6b, resolution 2.5Å" /> | caption="1b6b, resolution 2.5Å" /> | ||
'''MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTIC MECHANISM'''<br /> | '''MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTIC MECHANISM'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Conversion of serotonin to N-acetylserotonin, the precursor of the | + | Conversion of serotonin to N-acetylserotonin, the precursor of the circadian neurohormone melatonin, is catalyzed by serotonin N-acetyltransferase (AANAT) in a reaction requiring acetyl coenzyme A (AcCoA). AANAT is a globular protein consisting of an eight-stranded beta sheet flanked by five alpha helices; a conserved motif in the center of the beta sheet forms the cofactor binding site. Three polypeptide loops converge above the AcCoA binding site, creating a hydrophobic funnel leading toward the cofactor and serotonin binding sites in the protein interior. Two conserved histidines not found in other NATs are located at the bottom of the funnel in the active site, suggesting a catalytic mechanism for acetylation involving imidazole groups acting as general acid/base catalysts. |
==About this Structure== | ==About this Structure== | ||
| - | 1B6B is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ovis_aries Ovis aries]. Active as [http://en.wikipedia.org/wiki/Aralkylamine_N-acetyltransferase Aralkylamine N-acetyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.87 2.3.1.87] Full crystallographic information is available from [http:// | + | 1B6B is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ovis_aries Ovis aries]. Active as [http://en.wikipedia.org/wiki/Aralkylamine_N-acetyltransferase Aralkylamine N-acetyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.3.1.87 2.3.1.87] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1B6B OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Dyda, F.]] | [[Category: Dyda, F.]] | ||
| - | [[Category: Hickman, A | + | [[Category: Hickman, A B.]] |
| - | [[Category: Klein, D | + | [[Category: Klein, D C.]] |
[[Category: acetyltransferase]] | [[Category: acetyltransferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:00 2008'' |
Revision as of 09:52, 21 February 2008
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MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTIC MECHANISM
Overview
Conversion of serotonin to N-acetylserotonin, the precursor of the circadian neurohormone melatonin, is catalyzed by serotonin N-acetyltransferase (AANAT) in a reaction requiring acetyl coenzyme A (AcCoA). AANAT is a globular protein consisting of an eight-stranded beta sheet flanked by five alpha helices; a conserved motif in the center of the beta sheet forms the cofactor binding site. Three polypeptide loops converge above the AcCoA binding site, creating a hydrophobic funnel leading toward the cofactor and serotonin binding sites in the protein interior. Two conserved histidines not found in other NATs are located at the bottom of the funnel in the active site, suggesting a catalytic mechanism for acetylation involving imidazole groups acting as general acid/base catalysts.
About this Structure
1B6B is a Single protein structure of sequence from Ovis aries. Active as Aralkylamine N-acetyltransferase, with EC number 2.3.1.87 Full crystallographic information is available from OCA.
Reference
Melatonin biosynthesis: the structure of serotonin N-acetyltransferase at 2.5 A resolution suggests a catalytic mechanism., Hickman AB, Klein DC, Dyda F, Mol Cell. 1999 Jan;3(1):23-32. PMID:10024876
Page seeded by OCA on Thu Feb 21 11:52:00 2008
