Sandbox Reserved 653: Difference between revisions

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'''Structure:'''

The structure of Aspartate Aminotransferase has been determined through studies using X-ray crystallography. AST contains both α-helices packed on either side of a central sheet of β-strands in each of its domains. It is seen that AST has two identical subunits. Each subunit is approximately 300 residues long and each is composed of both a small and large domain. In addition a third domain is present which consists of the N-terminal residues 3-14; these residues link and stabilize the two subunits by forming a strand. Pyridoxial phosphate (PLP), the cofactor for AST binds to the large domain, interacting with the amino group of the Lys258 residue. It also interacts through hydrogen bonding with the Asp222 and Tyr 225 residues within the large domain. The small domain is responsible for the shift of the enzyme from an open conformation to closed conformation. This shift is based on the binding of the substrate. <scene name='Sandbox_Reserved_653/~~Active_Sites~~/1'>Active Sites </scene> are located between the two domains near the interface. There are two independent active sites each contains two arginine residues which are responsible for the enzyme’s specificity for the substrate. The first is Arg 292 which forms complexes with carboxylate side chains and the second is ARg286 which interacts with the alpha carobxylate group of the substrate.

The structure of Aspartate Aminotransferase has been determined through studies using X-ray crystallography. AST contains both α-helices packed on either side of a central sheet of β-strands in each of its domains. It is seen that AST has two identical subunits. Each subunit is approximately 300 residues long and each is composed of both a small and large domain. In addition a third domain is present which consists of the N-terminal residues 3-14; these residues link and stabilize the two subunits by forming a strand. Pyridoxial phosphate (PLP), the cofactor for AST binds to the large domain, interacting with the amino group of the Lys258 residue. It also interacts through hydrogen bonding with the Asp222 and Tyr 225 residues within the large domain. The small domain is responsible for the shift of the enzyme from an open conformation to closed conformation. This shift is based on the binding of the substrate. <scene name='Sandbox_Reserved_653/Active_sites/1'>Active Sites </scene> are located between the two domains near the interface. There are two independent active sites each contains two arginine residues which are responsible for the enzyme’s specificity for the substrate. The first is Arg 292 which forms complexes with carboxylate side chains and the second is ARg286 which interacts with the alpha carobxylate group of the substrate.

Sandbox Reserved 653: Difference between revisions

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Revision as of 02:33, 27 November 2012 view source Hanan Busaileh (talk \| contribs) 39 edits No edit summary ← Older edit		Revision as of 02:34, 27 November 2012 view source Hanan Busaileh (talk \| contribs) 39 edits No edit summary Newer edit →
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	'''Structure:'''		'''Structure:'''
	The structure of Aspartate Aminotransferase has been determined through studies using X-ray crystallography. AST contains both α-helices packed on either side of a central sheet of β-strands in each of its domains. It is seen that AST has two identical subunits. Each subunit is approximately 300 residues long and each is composed of both a small and large domain. In addition a third domain is present which consists of the N-terminal residues 3-14; these residues link and stabilize the two subunits by forming a strand. Pyridoxial phosphate (PLP), the cofactor for AST binds to the large domain, interacting with the amino group of the Lys258 residue. It also interacts through hydrogen bonding with the Asp222 and Tyr 225 residues within the large domain. The small domain is responsible for the shift of the enzyme from an open conformation to closed conformation. This shift is based on the binding of the substrate. <scene name='Sandbox_Reserved_653/~~Active_Sites~~/1'>Active Sites </scene> are located between the two domains near the interface. There are two independent active sites each contains two arginine residues which are responsible for the enzyme’s specificity for the substrate. The first is Arg 292 which forms complexes with carboxylate side chains and the second is ARg286 which interacts with the alpha carobxylate group of the substrate.		The structure of Aspartate Aminotransferase has been determined through studies using X-ray crystallography. AST contains both α-helices packed on either side of a central sheet of β-strands in each of its domains. It is seen that AST has two identical subunits. Each subunit is approximately 300 residues long and each is composed of both a small and large domain. In addition a third domain is present which consists of the N-terminal residues 3-14; these residues link and stabilize the two subunits by forming a strand. Pyridoxial phosphate (PLP), the cofactor for AST binds to the large domain, interacting with the amino group of the Lys258 residue. It also interacts through hydrogen bonding with the Asp222 and Tyr 225 residues within the large domain. The small domain is responsible for the shift of the enzyme from an open conformation to closed conformation. This shift is based on the binding of the substrate. <scene name='Sandbox_Reserved_653/Active_sites/1'>Active Sites </scene> are located between the two domains near the interface. There are two independent active sites each contains two arginine residues which are responsible for the enzyme’s specificity for the substrate. The first is Arg 292 which forms complexes with carboxylate side chains and the second is ARg286 which interacts with the alpha carobxylate group of the substrate.