1b6b: Difference between revisions

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[[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1b6b, resolution 2.5Å" />

'''MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTIC MECHANISM'''<br />

==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.

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 [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://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1B6B OCA].

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==

Line 15:

[[Category: Single protein]]

[[Category: Dyda, F.]]

[[Category: Hickman, A.B.]]

[[Category: Hickman, A B.]]

[[Category: Klein, D.C.]]

[[Category: Klein, D C.]]

[[Category: acetyltransferase]]

''Page seeded by [http://~~ispc~~.weizmann.ac.il/oca OCA ] on ~~Tue Nov 20~~ 11:23:~~48 2007~~''

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:00 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1b6b.gif|left|200px]]<br /><applet load="1b6b" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1b6b, resolution 2.5&Aring;" />
 '''MELATONIN BIOSYNTHESIS: THE STRUCTURE OF SEROTONIN N-ACETYLTRANSFERASE AT 2.5 A RESOLUTION SUGGESTS A CATALYTIC MECHANISM'''<br />
 ==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.
+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==
-B6B 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://ispc.weizmann.ac.il/oca-bin/ocashort?id=1B6B OCA].
+B6B 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==
@@ Line 15: / Line 15: @@
 [[Category: Single protein]]
 [[Category: Dyda, F.]]
-[[Category: Hickman, A.B.]]
+[[Category: Hickman, A B.]]
-[[Category: Klein, D.C.]]
+[[Category: Klein, D C.]]
 [[Category: acetyltransferase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 11:23:48 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:52:00 2008''