Template:Team:Bonn:NetworkData

content.parents=[12];

content.parents=[12];

content.titleShort = "ClpXP protease";

content.titleShort = "ClpXP protease";

content.summary= "The ClpXP protein complex is an AAA+ protease, which means that it uses the energy of ATP hydrolysis to unfold and degenerate marked proteins.";

content.summary= "The ClpXP protein complex is an AAA+ protease, which means that it uses the energy of ATP hydrolysis to unfold and degenerate marked proteins.";

content.text= "<b> Introduction: </b> </br>The ClpXP protein complex is an AAA+ protease, which means that it uses the energy of ATP hydrolysis to unfold and degenerate marked proteins. The genetic code of this complex is highly conserved and can be found in human cells as well as in the bacteria Escherichia coli. The degradation system was discovered in the early 1990's and is now well established ^{<a href='#13.1'>13.1</a>}.In our project, we used ClpXP to degrade specific proteins in order to control their amount and effect. Therefor, we utilized the common adaptor sspB.This protein recognizes substrates tagged with ssrA . In order to have a better control, we actually made use of a sspB split system. For more detailed information about the ClpXP degradation system in our project go to ClpXP general. </br> </br> <b> Structure:  </b> </br> The ClpXP complex consists of two functional and structural different parts. The ClpX protein, an ATPase, is a hexameric ring (Fig.1) with a pore in the center<div align='lef'><img src='https://static.igem.org/mediawiki/2013/9/98/Bonn_Clp_Fig1.jpg' height='348' width='320'>Fig. 1: the hexameric ring of ClpX, each color represents a subunit, from  &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554&quot;</div> </br> Each subunit contains a N-terminal domain (Fig.2, B), which assumes the adaptor recognition and is stabilized by coordinated zinc atoms.However, the important part of a subunit is the AAA+ module (Fig.2, C), divided in a large and a small domain. <div align='left'><img src='https://static.igem.org/mediawiki/2013/d/d0/BonnClp_Fig2.jpg' height='262' width='499'>Fig. 2: structure of a ClpX subunit, B: the N-terminal domain with brown zinc atoms, C: the AAA+ module, from  &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophy Acta, 2012, PMCID: PMC3209554&quot;</div> </br> Between these domains the ATP binding site can be found, but not every subunit is able to bind the nucleotide. The arrangement of ATP binding and not-binding subunits in the hexameric ring is essential for the tertiary structure and the conformation changes after hydrolysis. The ClpP protein is a tetradecameric peptidase (Fig. 3, A and B).The subunits are arranged as two heptameric rings, one ring stacked on top of the other, with also a narrow pore in the center. This pore leads into the proteolytic chamber, which is barrel-shaped. Every subunit accommodates a classical Ser-His-Asp catalytic triad and oxyanion hole inside the chamber. Those proteolytic acitve  sites (Fig. 3, C) can form several hydrogen bonds to the substrate^{<a href='#13.2'>13.2</a>}. <div align='left'><img src='https://static.igem.org/mediawiki/2013/0/06/BonnClp_Fig3.jpg' height='401' width='382'>Fig. 3: structure of ClpP, A: side view with stabilizing residues (blue), B: top view with the pore (red), C: active site of a subunit with a bonded substrate, from &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Bakeret al, Biochim Bi phys Acta, 2012, PMCID: PMC3209554&quot;</div> </br> </br> </br><b> Functions: </b> </br>The ClpXP complex has three tasks to fulfill: </br> </br>1. Binding: The substrate binding process at the ClpX unit is normally conducted with the aid of an adaptor protein.This protein identifies tagged substrates and delivers them to the complex (Fig. 4, left). In order to transfer the protein,the adaptor also binds to the ClpX unit (Fig. 4, right), so that parts of the tag get approximated to a special binding site on the complex. After the linking between the tag and the binding site has been performed, the unfolding starts.The binding process also works without an adaptor protein, but an adaptor enhances the degratation by improving enzyme-substrate affinity. </br> </br> 2. Unfolding and translocation: The translocation of polypeptids through the ClpX unit to the ClpP chamber is an active process using energy from ATP-binding and -hydrolysing cycles. Therefor are several ATP molecules linked to the ClpXprotein. The separation of one phosphate molecule results in conformation changes, which pulls the linked protein more inside the pore located in the center of ClpX. The remaining ADP has to be replaced by a new ATP molecule before the cycle can start again. Meanwhile the unfolding is driven automatically, because the large tagged protein has to fit into the narrow pore, which forces the three-dimensional structure to become linear. </br> </br> 3. Degradation: The axial pore of the ClpP unit is also very narrow, allowing the entry of only small unfolded peptides into the proteolytic chamber. Inside the chamber, the substrate binds to an active site over several hydrogen bonds. It also can be linked to multiple active sites. In this position, proteins are cleaved in a maximum speed of around 10,000 proteins per minute by ClpP alone. If the ClpX unit is added, the rate is with ~0.2 proteins per minute and 0.3 &my;M substrate much lower, because the unfolding process takes longer time^{<a href='#13.3'>[13.3]</a>}^{<a href='13.4'>13.4</a>}. </br> </br> <div align='left'><img src='https://static.igem.org/mediawiki/2013/b/b8/BonnClp_Fig4.jpg' height='311' width='628'>Fig. 4: Model of the degradation process with the sspB adaptor, from &quot;Engineering controllable protein degradation, McGinness et al, Molecular cell, 2006, PMID:16762842'</div> <h2><b> References </b> </h2></br> </br> <p><a id='13.1'>13.1</a> ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554</br> <a id='13.2'>13.2</a> See above </br> <a id='13.3'>13.3</a> See above </br> <a id='13.4'>13.4</a> Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes DeliveryComplexes with the AAA ClpXP Protease, Wah et al, 2003, Molecular cell, PMID: 14536075</p></br>";  

content.text= "<b> Introduction: </b> </br>The ClpXP protein complex is an AAA+ protease, which means that it uses the energy of ATP hydrolysis to unfold and degenerate marked proteins. The genetic code of this complex is highly conserved and can be found in human cells as well as in the bacteria Escherichia coli. The degradation system was discovered in the early 1990's and is now well established ^{<a href='#13.1'>13.1</a>}.In our project, we used ClpXP to degrade specific proteins in order to control their amount and effect. Therefor, we utilized the common adaptor sspB.This protein recognizes substrates tagged with ssrA . In order to have a better control, we actually made use of a sspB split system. For more detailed information about the ClpXP degradation system in our project go to ClpXP general. </br> </br> <b> Structure:  </b> </br> The ClpXP complex consists of two functional and structural different parts. The ClpX protein, an ATPase, is a hexameric ring (Fig.1) with a pore in the center<div align='lef'><img src='https://static.igem.org/mediawiki/2013/9/98/Bonn_Clp_Fig1.jpg' height='348' width='320'>Fig. 1: the hexameric ring of ClpX, each color represents a subunit, from  &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554&quot;</div> </br> Each subunit contains a N-terminal domain (Fig.2, B), which assumes the adaptor recognition and is stabilized by coordinated zinc atoms.However, the important part of a subunit is the AAA+ module (Fig.2, C), divided in a large and a small domain. <div align='left'><img src='https://static.igem.org/mediawiki/2013/d/d0/BonnClp_Fig2.jpg' height='262' width='499'>Fig. 2: structure of a ClpX subunit, B: the N-terminal domain with brown zinc atoms, C: the AAA+ module, from  &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophy Acta, 2012, PMCID: PMC3209554&quot;</div> </br> Between these domains the ATP binding site can be found, but not every subunit is able to bind the nucleotide. The arrangement of ATP binding and not-binding subunits in the hexameric ring is essential for the tertiary structure and the conformation changes after hydrolysis. The ClpP protein is a tetradecameric peptidase (Fig. 3, A and B).The subunits are arranged as two heptameric rings, one ring stacked on top of the other, with also a narrow pore in the center. This pore leads into the proteolytic chamber, which is barrel-shaped. Every subunit accommodates a classical Ser-His-Asp catalytic triad and oxyanion hole inside the chamber. Those proteolytic acitve  sites (Fig. 3, C) can form several hydrogen bonds to the substrate^{<a href='#13.2'>13.2</a>}. <div align='left'><img src='https://static.igem.org/mediawiki/2013/0/06/BonnClp_Fig3.jpg' height='401' width='382'>Fig. 3: structure of ClpP, A: side view with stabilizing residues (blue), B: top view with the pore (red), C: active site of a subunit with a bonded substrate, from &quot;ClpXP, an ATP-powered unfolding and protein-degradation machine, Bakeret al, Biochim Bi phys Acta, 2012, PMCID: PMC3209554&quot;</div> </br> </br> </br><b> Functions: </b> </br>The ClpXP complex has three tasks to fulfill: </br> </br>1. Binding: The substrate binding process at the ClpX unit is normally conducted with the aid of an adaptor protein.This protein identifies tagged substrates and delivers them to the complex (Fig. 4, left). In order to transfer the protein,the adaptor also binds to the ClpX unit (Fig. 4, right), so that parts of the tag get approximated to a special binding site on the complex. After the linking between the tag and the binding site has been performed, the unfolding starts.The binding process also works without an adaptor protein, but an adaptor enhances the degratation by improving enzyme-substrate affinity. </br> </br> 2. Unfolding and translocation: The translocation of polypeptids through the ClpX unit to the ClpP chamber is an active process using energy from ATP-binding and -hydrolysing cycles. Therefor are several ATP molecules linked to the ClpXprotein. The separation of one phosphate molecule results in conformation changes, which pulls the linked protein more inside the pore located in the center of ClpX. The remaining ADP has to be replaced by a new ATP molecule before the cycle can start again. Meanwhile the unfolding is driven automatically, because the large tagged protein has to fit into the narrow pore, which forces the three-dimensional structure to become linear. </br> </br> 3. Degradation: The axial pore of the ClpP unit is also very narrow, allowing the entry of only small unfolded peptides into the proteolytic chamber. Inside the chamber, the substrate binds to an active site over several hydrogen bonds. It also can be linked to multiple active sites. In this position, proteins are cleaved in a maximum speed of around 10,000 proteins per minute by ClpP alone. If the ClpX unit is added, the rate is with ~0.2 proteins per minute and 0.3 &my;M substrate much lower, because the unfolding process takes longer time^{<a href='#13.3'>[13.3]</a>}^{<a href='13.4'>13.4</a>}. </br> </br> <div align='left'><img src='https://static.igem.org/mediawiki/2013/b/b8/BonnClp_Fig4.jpg' height='311' width='628'>Fig. 4: Model of the degradation process with the sspB adaptor, from &quot;Engineering controllable protein degradation, McGinness et al, Molecular cell, 2006, PMID:16762842'</div> <h2><b> References </b> </h2></br> </br> <p><a id='13.1'>13.1</a> ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554</br> <a id='13.2'>13.2</a> See above </br> <a id='13.3'>13.3</a> See above </br> <a id='13.4'>13.4</a> Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes DeliveryComplexes with the AAA ClpXP Protease, Wah et al, 2003, Molecular cell, PMID: 14536075</p></br>";  

content.parents=[12];

content.parents=[12];

content.titleShort = "Ec. sspB adaptor"

content.titleShort = "Ec. sspB adaptor"

content.summary= "The sspB protein is an adaptor responsible for delivering ssrA-tagged substrates to the ClpXP protease in order to enhance their degradation";

content.summary= "The sspB protein is an adaptor responsible for delivering ssrA-tagged substrates to the ClpXP protease in order to enhance their degradation";

content.text= "<b>Introduction </b> </br> The sspB protein is an adaptor responsible for delivering ssrA-tagged substrates to the ClpXP protease in order to enhance their degradation.Thus, bacterias like E.coli or C.crescentus regulate the concentration of marked proteins and also are in control of their quality. Even though degeneration of tagged substrates is possible without sspB, sspB delivering is a common process, because it improves the affinity between ssrA and ClpXP^{<a href='#14.1'>14.1</a>}. </br> In our project, we used a sspB split variant instead of the normal sspB in order to control cleaving rate. The two parts of this version only stay divided until we ray them with light of a special wavelength. After that, the fractions form an unit and can function normal from now on as described below. </br> </br><b>Structure </b> </br>The sspB adaptor is a homomeric dimer (Fig. 1), which means that itconsists of two identical domains. Together the domains form a pore with the ssrA binding sites inside. Each domain also owns a C-terminal tail ending in a ClpX binding module, called XP. The amino-acid sequence of XP is highly conserved so that mutations in it mostly cause extremely decrease in activity, whereas the linker sequence differs from species to species ^{<a href='#14.2'>14.2</a>}^{<a href='#14.3'>14.3</a>}. <div align='left'><img src='https://static.igem.org/mediawiki/2013/5/5c/BonnsspB_Fig2.jpg' height='202' width='403'>Fig. 1: Ribbon diagramm of the sspB dimer with a bound srrA-tagged protein, from 'Versatile modes of peptide recognition by the AAA+ adaptor protein SspB, Levchenko et al, 2005, nature structural and molecular biology, PMID: 15880122</div> </br> </br></br></br><b>Function</b></br> SspB enhances degradation of ssrA-tagged proteins by lowering the K_M. Thus, with a given substrate concentration sspB-mediated cleaving runs faster than without sspB (Fig. 2) </br> <div align='left'><img src='https://static.igem.org/mediawiki/2013/d/d8/BonnSspB_Fig1.jpg' height='232' width='371'>Fig. 2: Diagramm, shows the degradation rate of GFP-ssrA without sspB, with sspB and with two mutations, the given substrate concentration is 0.3 &my;M, from 'Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes Delivery Complexes with the AAA ClpXP Protease, Wah et al, Molecular Cell, 2003, PMID: 14536075' </div></br> Therefor, the sspB dimer contains a pore and while 'AADENY' is linked with the inside, the 'LAA'-domain (respectively 'DAS') faces outwards, free to bind ClpX (Fig. 3).</br> The affinity of this binding amounts around 20 &my;M, which suggests a relative strong  connection. The two extremely flexible ClpX binding tails with XP at the C-terminal end  dock on ClpX. So the 'LAA'- domain lies closely to ClpX's axial pore and can be bound to it. <div align='left'><img src='https://static.igem.org/mediawiki/2013/7/7c/BonnSsra_fig3.jpg' height='151' width='116'>Fig. 3: Model of sspB with a bound ssrA-tagged substrate, from 'Engineering controllable protein degradation, McGinness et al, Molecular cell, 2006, PMID:16762842' </div></br> To sum up, there are three bonds connecting the ssrA-sspB-ClpX-complex and making it relative stable: ssrA with sspB, sspB with ClpX and ssrA with ClpX. Hence follows a lower K_M than the direct binding process has^{<a href='#14.4'>14.4</a>}^{<a href='#14.5'>14.5</a>}. <h2> References </h2> <a id='14.1'>14.1</a>Bivalent Tethering of SspB to ClpXP Is Required for Efficient Substrate Delivery: A Protein-Design Study, Bolon et al, 2004, Molecular Cell, PMID: 14967151 </br><a id='14.2'>14.2</a>see above </br> <a id='14.3'>14.3</a> Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes Delivery Complexes with the AAA ClpXP Protease, Wah et al, Molecular Cell, 2003, PMID: 14536075 </br> <a id='14.4'>14.4</a> see above</br> <a id='14.6'>[14.5]</a> Altered Tethering of the SspB Adaptor to the ClpXP Protease Causes Changes in Substrate Delivery, McGinnes KE et al, The journal of Biological Chemistry, 2007, PMID: 17317664 </br> <a id='14.4'>14.4</a>  ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554</br>";  

content.text= "<b>Introduction </b> </br> The sspB protein is an adaptor responsible for delivering ssrA-tagged substrates to the ClpXP protease in order to enhance their degradation.Thus, bacterias like E.coli or C.crescentus regulate the concentration of marked proteins and also are in control of their quality. Even though degeneration of tagged substrates is possible without sspB, sspB delivering is a common process, because it improves the affinity between ssrA and ClpXP^{<a href='#14.1'>14.1</a>}. </br> In our project, we used a sspB split variant instead of the normal sspB in order to control cleaving rate. The two parts of this version only stay divided until we ray them with light of a special wavelength. After that, the fractions form an unit and can function normal from now on as described below. </br> </br><b>Structure </b> </br>The sspB adaptor is a homomeric dimer (Fig. 1), which means that itconsists of two identical domains. Together the domains form a pore with the ssrA binding sites inside. Each domain also owns a C-terminal tail ending in a ClpX binding module, called XP. The amino-acid sequence of XP is highly conserved so that mutations in it mostly cause extremely decrease in activity, whereas the linker sequence differs from species to species ^{<a href='#14.2'>14.2</a>}^{<a href='#14.3'>14.3</a>}. <div align='left'><img src='https://static.igem.org/mediawiki/2013/5/5c/BonnsspB_Fig2.jpg' height='202' width='403'>Fig. 1: Ribbon diagramm of the sspB dimer with a bound srrA-tagged protein, from 'Versatile modes of peptide recognition by the AAA+ adaptor protein SspB, Levchenko et al, 2005, nature structural and molecular biology, PMID: 15880122</div> </br> </br></br></br><b>Function</b></br> SspB enhances degradation of ssrA-tagged proteins by lowering the K_M. Thus, with a given substrate concentration sspB-mediated cleaving runs faster than without sspB (Fig. 2) </br> <div align='left'><img src='https://static.igem.org/mediawiki/2013/d/d8/BonnSspB_Fig1.jpg' height='232' width='371'>Fig. 2: Diagramm, shows the degradation rate of GFP-ssrA without sspB, with sspB and with two mutations, the given substrate concentration is 0.3 &my;M, from 'Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes Delivery Complexes with the AAA ClpXP Protease, Wah et al, Molecular Cell, 2003, PMID: 14536075' </div></br> Therefor, the sspB dimer contains a pore and while 'AADENY' is linked with the inside, the 'LAA'-domain (respectively 'DAS') faces outwards, free to bind ClpX (Fig. 3).</br> The affinity of this binding amounts around 20 &my;M, which suggests a relative strong  connection. The two extremely flexible ClpX binding tails with XP at the C-terminal end  dock on ClpX. So the 'LAA'- domain lies closely to ClpX's axial pore and can be bound to it. <div align='left'><img src='https://static.igem.org/mediawiki/2013/7/7c/BonnSsra_fig3.jpg' height='151' width='116'>Fig. 3: Model of sspB with a bound ssrA-tagged substrate, from 'Engineering controllable protein degradation, McGinness et al, Molecular cell, 2006, PMID:16762842' </div></br> To sum up, there are three bonds connecting the ssrA-sspB-ClpX-complex and making it relative stable: ssrA with sspB, sspB with ClpX and ssrA with ClpX. Hence follows a lower K_M than the direct binding process has^{<a href='#14.4'>14.4</a>}^{<a href='#14.5'>14.5</a>}. <h2> References </h2> <a id='14.1'>14.1</a>Bivalent Tethering of SspB to ClpXP Is Required for Efficient Substrate Delivery: A Protein-Design Study, Bolon et al, 2004, Molecular Cell, PMID: 14967151 </br><a id='14.2'>14.2</a>see above </br> <a id='14.3'>14.3</a> Flexible Linkers Leash the Substrate Binding Domain of SspB to a Peptide Module that Stabilizes Delivery Complexes with the AAA ClpXP Protease, Wah et al, Molecular Cell, 2003, PMID: 14536075 </br> <a id='14.4'>14.4</a> see above</br> <a id='14.6'>[14.5]</a> Altered Tethering of the SspB Adaptor to the ClpXP Protease Causes Changes in Substrate Delivery, McGinnes KE et al, The journal of Biological Chemistry, 2007, PMID: 17317664 </br> <a id='14.4'>14.4</a>  ClpXP, an ATP-powered unfolding and protein-degradation machine, Baker et al, Biochim Biophys Acta, 2012, PMCID: PMC3209554</br>";