Human SUMO E1 complex: Difference between revisions
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<StructureSection load='3kyc' size= | <StructureSection load='3kyc' size="400" color="" spin="on" Scene= caption='Human SUMO-activating enzyme subunits 1 & 2 complex with SUMO-1, deoxy-sulfamoylamino-adenosine and Zn+2 ion [[3kyc]] > | ||
Ubiquitin (Ub) and ubiquitin-like (Ubl) proteins attached to their target proteins and modulating the activities of those targets in various ways. Three types of evolutionarily conserved enzymes — E1 activating enzymes, E2 conjugating enzymes and E3 ligase enzymes — act sequentially through parallel yet distinct pathways to conjugate ubiquitin and Ubl proteins, such as SUMO and NEDD8, to their targets. The E1 enzyme uses the <scene name='3kyc/Cv/3'>adenosine triphosphate (ATP)</scene> and magnesium to adenylate the C-terminal Ub/Ubl glycine, releasing pyrophosphate and resulting in <scene name='3kyc/Cv/8'>adenosine monophosphate (AMP)</scene>. A non-hydrolysable <scene name='3kyc/Cv/4'>mimic of the acyl adenylate intermediate (AMSN)</scene> and <scene name='3kyc/Cv/5'>mimic of the tetrahedral intermediate (AVSN)</scene> were constructed. In both these compounds the atom of <font color='orange'><b>phosphorus</b></font> is replaced by sulfur (colored <span style="color:yellow;background-color:black;font-weight:bold;">yellow</span>). | Ubiquitin (Ub) and ubiquitin-like (Ubl) proteins attached to their target proteins and modulating the activities of those targets in various ways. Three types of evolutionarily conserved enzymes — E1 activating enzymes, E2 conjugating enzymes and E3 ligase enzymes — act sequentially through parallel yet distinct pathways to conjugate ubiquitin and Ubl proteins, such as SUMO and NEDD8, to their targets. The E1 enzyme uses the <scene name='3kyc/Cv/3'>adenosine triphosphate (ATP)</scene> and magnesium to adenylate the C-terminal Ub/Ubl glycine, releasing pyrophosphate and resulting in <scene name='3kyc/Cv/8'>adenosine monophosphate (AMP)</scene>. A non-hydrolysable <scene name='3kyc/Cv/4'>mimic of the acyl adenylate intermediate (AMSN)</scene> and <scene name='3kyc/Cv/5'>mimic of the tetrahedral intermediate (AVSN)</scene> were constructed. In both these compounds the atom of <font color='orange'><b>phosphorus</b></font> is replaced by sulfur (colored <span style="color:yellow;background-color:black;font-weight:bold;">yellow</span>). | ||
The <scene name='3kyc/Al/2'>structural alignment</scene> of the crystal structures for human SUMO E1 in complex with SUMO adenylate (AMSN) and tetrahedral intermediate (AVSN) analogues revealed opened conformation (<font color='orange'><b>SUMO1 in orange</b></font>, <font color='blue'><b>SAE1 colored in blue</b></font>, and <font color='darkviolet'><b>other domains in darkviolet</b></font>) and closed conformation (<span style="color:yellow;background-color:black;font-weight:bold;">SUMO1 in yellow</span>, <font color='cyan'><b>SAE1 colored in cyan</b></font>, and <font color='magenta'><b>other domains in magenta</b></font>), respectively. In the <scene name='3kyc/Al/7'>open conformation</scene> ([[3kyc]]) the distance between Cys domain (including Cys173) and mimic of the acyl adenylate intermediate AMSN is very long, while in the <scene name='3kyc/Al/6'>closed conformation</scene> ([[3kyd]]), the catalytic Cys173 is posioned near AVSN and SUMO1, so the overall structure revealed dramatic rearrangement. This large conformational change forms the <scene name='3kyc/Al/8'>E1~SUMO1-AVSN tetrahedral intermediate analogue</scene>. | The <scene name='3kyc/Al/2'>structural alignment</scene> of the crystal structures for human SUMO E1 in complex with SUMO adenylate (AMSN) and tetrahedral intermediate (AVSN) analogues revealed opened conformation (<font color='orange'><b>SUMO1 in orange</b></font>, <font color='blue'><b>SAE1 colored in blue</b></font>, and <font color='darkviolet'><b>other domains in darkviolet</b></font>) and closed conformation (<span style="color:yellow;background-color:black;font-weight:bold;">SUMO1 in yellow</span>, <font color='cyan'><b>SAE1 colored in cyan</b></font>, and <font color='magenta'><b>other domains in magenta</b></font>), respectively. In the <scene name='3kyc/Al/7'>open conformation</scene> ([[3kyc]]) the distance between Cys domain (including Cys173) and mimic of the acyl adenylate intermediate AMSN is very long, while in the <scene name='3kyc/Al/6'>closed conformation</scene> ([[3kyd]]), the catalytic Cys173 is posioned near AVSN and SUMO1, so the overall structure revealed dramatic rearrangement. This large conformational change forms the <scene name='3kyc/Al/8'>E1~SUMO1-AVSN tetrahedral intermediate analogue</scene>. | ||