Sandbox Reserved 1070: Difference between revisions
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===Catalytic GGEEF Domain=== | ===Catalytic GGEEF Domain=== | ||
The GGEEF domain | The GGEEF domain of DgcZ is part of the GGDEF family of proteins that includes a conserved sequence, GG[DE][DE]F[2].The GGEEF domain is a homodimer consisting of a central five-stranded β-sheet surrounded by five α-helices. Each dimer contains an active half-site that, when combined together in a productive conformation, form the entire active site. Each half-site binds one GTP molecule. The guanyl base forms hydrogen bonds with Asp-173 and Asn-182 to hold it in the active site. A Mg<sup>2+</sup> ion stabilizes the negative charges on the phosphate groups. When in the productive conformation, each GTP is held in close proximity with the α-phosphate groups overlapping C3 of the ribose. This conformation allows the α-phospate of one GTP to react with the alcohol group on C3 of the ribose of the other GTP, resulting in a cyclization of the two molecules into c-di-GMP. The ribose of each guanosine triphosphate, and subsequent product c-di-GMP riboses, are held only loosely by the enzyme, while the phosphate groups are not bound at all. | ||
===Mechanism of Action=== | ===Mechanism of Action=== | ||