Nitric Oxide Synthase: Difference between revisions

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===Zinc===
===Zinc===


In order for Nos to be active it has to dimerize and bind H<sub>4</sub>B. The two monomers are held together by a single structural <scene name='Nitric_oxide_synthase/Zink/2'>zinc ion</scene> <applet load='2g6h' size='300' frame='true' align='right' caption='Zinc' />
In order for Nos to be active it has to dimerize and bind H<sub>4</sub>B. The two monomers are held together by a single structural <applet load='2g6h' size='300' frame='true' align='right' caption='Zinc' /><scene name='Nitric_oxide_synthase/Zink/2'>zinc ion</scene>
which is situated at the interface of the dimer.<ref>PMID: 10074942</ref>  The zinc ion is tetrahedrally coordinated and has four cysteins bound as ligands (two from each monomer - Cys109 and Cys104). Further, it is found that zinc binds together the oxygenase domains of the monomers. The zinc ion is found at region which connects the N-terminal hook and the subunit core. The coordination of zinc arranges the N-terminal hooks so that they interact with their own subunit. However, when there is no zinc ion present, two of the thiolate  
which is situated at the interface of the dimer.<ref>PMID: 10074942</ref>  The zinc ion is tetrahedrally coordinated and has four cysteins bound as ligands (two from each monomer - Cys109 and Cys104). Further, it is found that zinc binds together the oxygenase domains of the monomers. The zinc ion is found at region which connects the N-terminal hook and the subunit core. The coordination of zinc arranges the N-terminal hooks so that they interact with their own subunit. However, when there is no zinc ion present, two of the thiolate  
ligands form a disulfide bond connecting the two subunits<ref>PMID: 10562539</ref>.
ligands form a disulfide bond connecting the two subunits<ref>PMID: 10562539</ref>.