Sandbox Reserved 316: Difference between revisions

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{{STRUCTURE_3hle |  PDB=3hle  |  SCENE=  }}
 
==Introduction==
==Introduction==
[[Image:svs.jpg|200px|left|thumb|]]'''Simvastatin synthase''' (LovD) is a 46 kDa acyltransferase found in the lovastatin biosynthetic pathway and catalyzes the final step of lovastatin biosynthesis<ref name="paper4">PMID:
[[Image:svs.jpg|300px|left|thumb|]]'''Simvastatin synthase''' (LovD) is a 46 kDa acyltransferase found in the lovastatin biosynthetic pathway and catalyzes the final step of lovastatin biosynthesis<ref name="paper4">PMID:
17113998</ref>. Pictured here is the D5 mutant (Figure 1).
17113998</ref>. Pictured here is the generated double mutant C40A/C60N (G0), from wild type LovD (Figure 1).
 


This enzyme is isolated from the natural product biosynthetic pathways of [http://en.wikipedia.org/wiki/Aspergillus_terreus ''Aspergillus terreus''], specifically the polyketide biosynthetic pathway. Simvastatin Synthase  converts the inactive monacolin J acid (MJA) by dimethylbutyryl chloride to yield the protected form of simvastatin (Figure 2), which subsequently undergoes lactonization to yield [http://en.wikipedia.org/wiki/Simvastatin ''simvastatin'']<ref name="paper5">PMID:19875080</ref>.


This enzyme is isolated from the natural product biosynthetic pathways of ''Aspergillus terreus''. Simvastatin Synthase  converts the inactive monacolin J acid (<scene name='Sandbox_Reserved_316/Blah/2'>MJA</scene>) by dimethylbutyryl chloride to yield the protected form of simvastatin (Figure 2), which subsequently undergoes lactonization to yield simvastatin<ref name="paper5">PMID:19875080</ref>.
[[Image:Sim_mja.jpg]]  
[[Image:Sim_mja.jpg]]


LovD can also synthesize the blockbuster drug simvastatin using MJA and a synthetic α-dimethylbutyryl thioester<ref name="paper1">PMID:17277201</ref>.
LovD can also synthesize the blockbuster drug simvastatin using MJA and a synthetic α-dimethylbutyryl thioester<ref name="paper1">PMID:17277201</ref>.
==Exploring the structure==
==Exploring the structure==
LovD is a 413-amino acid protein predicted to have an α/β hydrolase fold based on primary sequence analysis<ref name="paper2">PMID:10334994</ref>.  
{{STRUCTURE_3hle |  PDB=3hle  |  SCENE=Sandbox_Reserved_316/Default/1}}
LovD has of two domains. The <scene name='Sandbox_Reserved_316/First_domain_1/1'>first domain</scene>, which consists of residues 1–92 and 204–413, is a central seven-stranded antiparallel β-sheet flanked by α-helices on either face<ref name="paper1">PMID:17277201</ref>. The <scene name='Sandbox_Reserved_316/Second_domain_1/1'>second domain</scene> is smaller, consists of residues 93–203 and is primarily α-helical<ref name="paper1">PMID:17277201</ref>.  
<scene name='Sandbox_Reserved_316/Default/1'>LovD</scene> is a 413-amino acid protein predicted to have an α/β hydrolase fold based on primary sequence analysis<ref name="paper2">PMID:10334994</ref>.  
LovD has of two domains. The <scene name='Sandbox_Reserved_316/Firsstdomain/1'>first domain</scene>, which consists of residues 1–92 and 204–413, is a central seven-stranded antiparallel β-sheet flanked by α-helices on either face<ref name="paper1">PMID:17277201</ref>. The  
<scene name='Sandbox_Reserved_316/Seconddomainn/1'>second domain</scene> is smaller, consists of residues 93–203 and is primarily α-helical<ref name="paper1">PMID:17277201</ref>.  


At the core of the enzyme, there are notable loops peripheral to the active site, both in size and architecture. In LovD, these loops give the impression of a ringshaped ridge or baseball catcher’s mitt over the active site with fingers composed of <scene name='Sandbox_Reserved_316/5_loops/1'>five loops</scene>: residues 114–125, 147–173, 243–258, 321–327, and 388–391<ref name="paper1">PMID:17277201</ref>.
At the core of the enzyme, there are notable loops peripheral to the active site, both in size and architecture. Upon ligand binding LovD undergoes a conformational change analogous to the closing of a catcher's mitt by these loops. This ringshaped ridge over the active site with fingers is composed of <scene name='Sandbox_Reserved_316/5_loops/2'>five loops</scene>: residues 114–125, 147–173, 243–258, 321–327, and 388–391<ref name="paper1">PMID:17277201</ref>.


LovD has <scene name='Sandbox_Reserved_316/Cysteines/1'>nine cysteines</scene> at the following positions: C40, C49, C60, C72, C89, C216, C266, C380, and C395<ref name="paper3">PMID:18988191</ref>.
LovD has <scene name='Sandbox_Reserved_316/Cysteines/2'>nine cysteines</scene> at the following positions: C40, C49, C60, C72, C89, C216, C266, C380, and C395<ref name="paper3">PMID:18988191</ref>.


==Significance==
==Additional Information==
<Structure load='1CI8' size='300' frame='true' align='right' caption='' scene='Sandbox_Reserved_316/Estb/1'/>
As simvastatin is an active pharmaceutical ingredient in the cholesterol-lowering drug Zocor®, its efficient synthesis from lovastatin, via LovD is intensely pursued <ref name="paper4">PMID:19875080</ref>.
As simvastatin is an active pharmaceutical ingredient in the cholesterol-lowering drug Zocor®, its efficient synthesis from lovastatin, via LovD is intensely pursued <ref name="paper4">PMID:19875080</ref>.
The protein-protein interaction between LovD and the acyl carrier protein domain of LovF facilitates the highly efficient tailoring reaction during LVA biosynthesis <ref name="paper4">PMID:
17113998</ref>. The α-''S''-methylbutyrate side chain is synthesized by the lovastatin diketide synthase (LDKS) LovF and then transferred by LovD regioselectively to the C8 hydroxyl of <scene name='Sandbox_Reserved_316/Blah/3'>MJA</scene><ref name="paper3">PMID:18988191</ref>.
Among enzymes that of known structures, <scene name='Sandbox_Reserved_316/Estb/1'>EstB</scene> (cephalosporin esterase), is homologous to LovD: 26% sequence identity <ref name="paper6">PMID:
11847270</ref>.


==References==
==References==
<references/>
<references/>

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