Nitric Oxide Synthase: Difference between revisions

In order for Nos to be active it has to dimerize and bind H4B. The two monomers are held together by a single structural zinc ion 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>.