1c3c: Difference between revisions

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T. MARITIMA ADENYLOSUCCINATE LYASE

OverviewOverview

Background: Adenylosuccinate lyase is an enzyme that plays a critical role in both cellular replication and metabolism via its action in the de novo purine biosynthetic pathway. Adenylosuccinate lyase is the only enzyme in this pathway to catalyze two separate reactions, enabling it to participate in the addition of a nitrogen at two different positions in adenosine monophosphate. Both reactions catalyzed by adenylosuccinate lyase involve the beta-elimination of fumarate. Enzymes that catalyze this type of reaction belong to a superfamily, the members of which are homotetramers. Because adenylosuccinate lyase plays an integral part in maintaining proper cellular metabolism, mutations in the human enzyme can have severe clinical consequences, including mental retardation with autistic features. Results: The 1.8 A crystal structure of adenylosuccinate lyase from Thermotoga maritima has been determined by multiwavelength anomalous dispersion using the selenomethionine-substituted enzyme. The fold of the monomer is reminiscent of other members of the beta-elimination superfamily. However, its active tetrameric form exhibits striking differences in active-site architecture and cleft size. Conclusions: This first structure of an adenylosuccinate lyase reveals that, along with the catalytic base (His141) and the catalytic acid (His68), Gln212 and Asn270 might play a vital role in catalysis by properly orienting the succinyl moiety of the substrates. We propose a model for the dual activity of adenylosuccinate lyase: a single 180 degrees bond rotation must occur in the substrate between the first and second enzymatic reactions. Modeling of the pathogenic human S413P mutation indicates that the mutation destabilizes the enzyme by disrupting the C-terminal extension.

About this StructureAbout this Structure

1C3C is a Single protein structure of sequence from Thermotoga maritima. Active as Adenylosuccinate lyase, with EC number 4.3.2.2 Full crystallographic information is available from OCA.

ReferenceReference

The structure of adenylosuccinate lyase, an enzyme with dual activity in the de novo purine biosynthetic pathway., Toth EA, Yeates TO, Structure. 2000 Feb 15;8(2):163-74. PMID:10673438

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 '''T. MARITIMA ADENYLOSUCCINATE LYASE'''<br />
 ==Overview==
-Background: Adenylosuccinate lyase is an enzyme that plays a critical role, in both cellular replication and metabolism via its action in the de novo, purine biosynthetic pathway. Adenylosuccinate lyase is the only enzyme in, this pathway to catalyze two separate reactions, enabling it to, participate in the addition of a nitrogen at two different positions in, adenosine monophosphate. Both reactions catalyzed by adenylosuccinate, lyase involve the beta-elimination of fumarate. Enzymes that catalyze this, type of reaction belong to a superfamily, the members of which are, homotetramers. Because adenylosuccinate lyase plays an integral part in, maintaining proper cellular metabolism, mutations in the human enzyme can, have severe clinical consequences, including mental retardation with, autistic features. Results: The 1.8 A crystal structure of, adenylosuccinate lyase from Thermotoga maritima has been determined by, multiwavelength anomalous dispersion using the, selenomethionine-substituted enzyme. The fold of the monomer is, reminiscent of other members of the beta-elimination superfamily. However, its active tetrameric form exhibits striking differences in active-site, architecture and cleft size. Conclusions: This first structure of an, adenylosuccinate lyase reveals that, along with the catalytic base, (His141) and the catalytic acid (His68), Gln212 and Asn270 might play a, vital role in catalysis by properly orienting the succinyl moiety of the, substrates. We propose a model for the dual activity of adenylosuccinate, lyase: a single 180 degrees bond rotation must occur in the substrate, between the first and second enzymatic reactions. Modeling of the, pathogenic human S413P mutation indicates that the mutation destabilizes, the enzyme by disrupting the C-terminal extension.
+Background: Adenylosuccinate lyase is an enzyme that plays a critical role in both cellular replication and metabolism via its action in the de novo purine biosynthetic pathway. Adenylosuccinate lyase is the only enzyme in this pathway to catalyze two separate reactions, enabling it to participate in the addition of a nitrogen at two different positions in adenosine monophosphate. Both reactions catalyzed by adenylosuccinate lyase involve the beta-elimination of fumarate. Enzymes that catalyze this type of reaction belong to a superfamily, the members of which are homotetramers. Because adenylosuccinate lyase plays an integral part in maintaining proper cellular metabolism, mutations in the human enzyme can have severe clinical consequences, including mental retardation with autistic features. Results: The 1.8 A crystal structure of adenylosuccinate lyase from Thermotoga maritima has been determined by multiwavelength anomalous dispersion using the selenomethionine-substituted enzyme. The fold of the monomer is reminiscent of other members of the beta-elimination superfamily. However, its active tetrameric form exhibits striking differences in active-site architecture and cleft size. Conclusions: This first structure of an adenylosuccinate lyase reveals that, along with the catalytic base (His141) and the catalytic acid (His68), Gln212 and Asn270 might play a vital role in catalysis by properly orienting the succinyl moiety of the substrates. We propose a model for the dual activity of adenylosuccinate lyase: a single 180 degrees bond rotation must occur in the substrate between the first and second enzymatic reactions. Modeling of the pathogenic human S413P mutation indicates that the mutation destabilizes the enzyme by disrupting the C-terminal extension.
 ==About this Structure==
-C3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Active as [http://en.wikipedia.org/wiki/Adenylosuccinate_lyase Adenylosuccinate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.3.2.2 4.3.2.2] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1C3C OCA].
+C3C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Active as [http://en.wikipedia.org/wiki/Adenylosuccinate_lyase Adenylosuccinate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.3.2.2 4.3.2.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C3C OCA].
 ==Reference==
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 [[Category: Single protein]]
 [[Category: Thermotoga maritima]]
-[[Category: Toth, E.A.]]
+[[Category: Toth, E A.]]
-[[Category: Yeates, T.O.]]
+[[Category: Yeates, T O.]]
 [[Category: lyase]]
 [[Category: purine biosynthesis]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:07:41 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:01:56 2008''