User:Matt Whelihan: Difference between revisions

Line 21:

Both the Japanese and North American luciferase variants consist of a single-chain 62 kDa monooxygenases with two distinct domains that are <scene name='User:Matt_Whelihan/Secondary_structure/1'>comprised</scene> of a mix of <font color='magenta'>alpha</font> and <font color='gold'>beta</font> secondary structures. The <scene name='User:Matt_Whelihan/N-terminal_domain/1'>N-terminal domain</scene> (residues 4-436) is comprised of of an antiparalell β-barrel and two β-sheets, flanked by α-helices which forms a typical <scene name='User:Matt_Whelihan/Rossmann/1'>Rossmann fold</scene> [http://images.google.com/imgres?imgurl=http://chem.csusb.edu/~dpedersn/C436/openbetarossman.jpg&imgrefurl=http://chem.csusb.edu/~dpedersn/C436/prot_struct_and_class.html&usg=__xOF4ifmAyJ5qm3UPaNKd9whKlu4=&h=539&w=719&sz=35&hl=en&start=5&um=1&tbnid=IMkWKmy0xzWcYM:&tbnh=105&tbnw=140&prev=/images%3Fq%3DRossman%2BFold%26hl%3Den%26safe%3Doff%26sa%3DN%26um%3D1] The

<scene name='User:Matt_Whelihan/C-terminal_domain/2'>C-terminal domain</scene> (residues 440-544) is comprises of a separate α-β hinge<ref>PMID:8805533</ref>. Firefly luciferases share significant sequence and mechanistic homology with peptide synthetases and acylCoA ligases. These enzymes belong to a superfamily of adenylate-forming enzymes that catalyze activation reactions between ATP and a carboxyl group of their substrates. This group of proteins shares an identifying motif <scene name='User:Matt_Whelihan/198-207/1'>(198SerSerGlySerThrGlyLeuProLysGly207)</scene> and has been termed the “acyl-adenylate/thioester-forming” enzyme family. Despite high sequence homology, there are only seven residues that are conserved across this superfamily (Gly200, Lys206, Glu344, Asp422, Arg437, Gly446, and Glu455). These residues are believed to be integral to the binding of ATP and the formation of an adenylate compound <ref>PMID:1351742</ref><ref>PMID:1447981</ref>. These residues however are located across the N and C-terminal domains, which in the structure, are too far apart to produce catalysis. This suggested suggest that the crystallized form was in the resting state of the enzyme and it was hypothesized that the C-terminal domain would close in on the active site cleft upon substrate binding. This closing of the active site combined with various hydrophobic residues seen packed around the active site suggested that catalysis may occur in the absence of water.

<scene name='User:Matt_Whelihan/C-terminal_domain/2'>C-terminal domain</scene> (residues 440-544) is comprises of a separate α-β hinge<ref>PMID:8805533</ref>. Firefly luciferases share significant sequence and mechanistic homology with peptide synthetases[http://www.rcsb.org/pdb/explore.do?structureId=2QUH] and acylCoA ligases[http://www.rcsb.org/pdb/explore.do?structureId=2HF0]. These enzymes belong to a superfamily of adenylate-forming enzymes that catalyze activation reactions between ATP and a carboxyl group of their substrates. This group of proteins shares an identifying motif <scene name='User:Matt_Whelihan/198-207/1'>(198SerSerGlySerThrGlyLeuProLysGly207)</scene> and has been termed the “acyl-adenylate/thioester-forming” enzyme family. Despite high sequence homology, there are only seven residues that are conserved across this superfamily (Gly200, Lys206, Glu344, Asp422, Arg437, Gly446, and Glu455). These residues are believed to be integral to the binding of ATP and the formation of an adenylate compound <ref>PMID:1351742</ref><ref>PMID:1447981</ref>. These residues however are located across the N and C-terminal domains, which in the structure, are too far apart to produce catalysis. This suggested suggest that the crystallized form was in the resting state of the enzyme and it was hypothesized that the C-terminal domain would close in on the active site cleft upon substrate binding. This closing of the active site combined with various hydrophobic residues seen packed around the active site suggested that catalysis may occur in the absence of water.

These seven highly conserved amino acids identify the <scene name='User:Matt_Whelihan/Active_site_residues/1'>active site</scene> which is located in the large hydrophobic cleft between the two adjacent N and C-terminal domains. <scene name='User:Matt_Whelihan/Cysteins/1'>Cysteine</scene>

User:Matt Whelihan: Difference between revisions

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 21: / Line 21: @@
 Both the Japanese and North American luciferase variants consist of a single-chain 62 kDa monooxygenases with two distinct domains  that are <scene name='User:Matt_Whelihan/Secondary_structure/1'>comprised</scene> of a mix of <font color='magenta'>alpha</font> and <font color='gold'>beta</font> secondary structures. The <scene name='User:Matt_Whelihan/N-terminal_domain/1'>N-terminal domain</scene> (residues 4-436) is comprised of of an antiparalell β-barrel and two β-sheets, flanked by α-helices which forms a typical <scene name='User:Matt_Whelihan/Rossmann/1'>Rossmann fold</scene> [http://images.google.com/imgres?imgurl=http://chem.csusb.edu/~dpedersn/C436/openbetarossman.jpg&imgrefurl=http://chem.csusb.edu/~dpedersn/C436/prot_struct_and_class.html&usg=__xOF4ifmAyJ5qm3UPaNKd9whKlu4=&h=539&w=719&sz=35&hl=en&start=5&um=1&tbnid=IMkWKmy0xzWcYM:&tbnh=105&tbnw=140&prev=/images%3Fq%3DRossman%2BFold%26hl%3Den%26safe%3Doff%26sa%3DN%26um%3D1] The
-<scene name='User:Matt_Whelihan/C-terminal_domain/2'>C-terminal domain</scene> (residues 440-544) is comprises of a separate α-β hinge<ref>PMID:8805533</ref>. Firefly luciferases share significant sequence and mechanistic homology with peptide synthetases and acylCoA ligases. These enzymes belong to a superfamily of adenylate-forming enzymes that catalyze activation reactions between ATP and a carboxyl group of their substrates. This group of proteins shares an identifying motif <scene name='User:Matt_Whelihan/198-207/1'>(198SerSerGlySerThrGlyLeuProLysGly207)</scene> and has been termed the “acyl-adenylate/thioester-forming” enzyme family. Despite high sequence homology, there are only seven residues that are conserved across this superfamily (Gly200, Lys206, Glu344, Asp422, Arg437, Gly446, and Glu455). These residues are believed to be integral to the binding of ATP and the formation of an adenylate compound <ref>PMID:1351742</ref><ref>PMID:1447981</ref>. These residues however are located across the N and C-terminal domains, which in the structure, are too far apart to produce catalysis. This suggested suggest that the crystallized form was in the resting state of the enzyme and it was hypothesized that the C-terminal domain would close in on the active site cleft upon substrate binding. This closing of the active site combined with various hydrophobic residues seen packed around the active site suggested that catalysis may occur in the absence of water.
+<scene name='User:Matt_Whelihan/C-terminal_domain/2'>C-terminal domain</scene> (residues 440-544) is comprises of a separate α-β hinge<ref>PMID:8805533</ref>. Firefly luciferases share significant sequence and mechanistic homology with peptide synthetases[http://www.rcsb.org/pdb/explore.do?structureId=2QUH] and acylCoA ligases[http://www.rcsb.org/pdb/explore.do?structureId=2HF0]. These enzymes belong to a superfamily of adenylate-forming enzymes that catalyze activation reactions between ATP and a carboxyl group of their substrates. This group of proteins shares an identifying motif <scene name='User:Matt_Whelihan/198-207/1'>(198SerSerGlySerThrGlyLeuProLysGly207)</scene> and has been termed the “acyl-adenylate/thioester-forming” enzyme family. Despite high sequence homology, there are only seven residues that are conserved across this superfamily (Gly200, Lys206, Glu344, Asp422, Arg437, Gly446, and Glu455). These residues are believed to be integral to the binding of ATP and the formation of an adenylate compound <ref>PMID:1351742</ref><ref>PMID:1447981</ref>. These residues however are located across the N and C-terminal domains, which in the structure, are too far apart to produce catalysis. This suggested suggest that the crystallized form was in the resting state of the enzyme and it was hypothesized that the C-terminal domain would close in on the active site cleft upon substrate binding. This closing of the active site combined with various hydrophobic residues seen packed around the active site suggested that catalysis may occur in the absence of water.
 These seven highly conserved amino acids identify the <scene name='User:Matt_Whelihan/Active_site_residues/1'>active site</scene> which is located in the large hydrophobic cleft between the two adjacent N and C-terminal domains. <scene name='User:Matt_Whelihan/Cysteins/1'>Cysteine</scene>