Sandbox Reserved 342: Difference between revisions
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=Mechanism and Catalysis= | =Mechanism and Catalysis= | ||
<Structure load='1a96' size='300' frame='true' align='right' caption='Insert caption here' scene='Insert optional scene name here' /> | <Structure load='1a96' size='300' frame='true' align='right' caption='Insert caption here' scene='Insert optional scene name here' /> | ||
In the | In the <scene name='Sandbox_Reserved_342/Mobile_loop/1'>mobile loop</scene> the XGPRT, there are several residues that are critical for substrate and catalysis<ref name="Vos"/>. The loop required for binding and catalysis is flexible, when XGPRT does not have products or substrates bound to it<ref name="Vos"/>. The flexibility of the residues in this loop assists movement of the loop towards the active site<ref name="Vos"/>. | ||
Magnesium and other divalent cations are necessary for catalysis because magnesium and PRib-PP binding play a critical role for the PRTase reaction<ref name="Vos"/>. The Mg:PRib-PP complex binds to the active site of PRTases<ref name="Vos"/>. In type I PRTases, XGPRT, catalysis proceeds via SN1 mechanism and it forms a oxocarbonium ion in the transition state<ref name="Vos"/>. It has been suggested, that the magnesium ion departs with the displaced pyrophosphate because there is no magnesium ion at the active site<ref name="Vos"/>. | Magnesium and other divalent cations are necessary for catalysis because magnesium and PRib-PP binding play a critical role for the PRTase reaction<ref name="Vos"/>. The Mg:PRib-PP complex binds to the active site of PRTases<ref name="Vos"/>. In type I PRTases, XGPRT, catalysis proceeds via SN1 mechanism and it forms a oxocarbonium ion in the transition state<ref name="Vos"/>. It has been suggested, that the magnesium ion departs with the displaced pyrophosphate because there is no magnesium ion at the active site<ref name="Vos"/>. | ||