PDBsum entry 1c25

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Hydrolase PDB id
Protein chain
161 a.a.
Waters ×82

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Key reference
Title Crystal structure of the catalytic domain of the human cell cycle control phosphatase, Cdc25a.
Authors E.B.Fauman, J.P.Cogswell, B.Lovejoy, W.J.Rocque, W.Holmes, V.G.Montana, H.Piwnica-Worms, M.J.Rink, M.A.Saper.
Ref. Cell, 1998, 93, 617-625. [DOI no: 10.1016/S0092-8674(00)81190-3]
PubMed id 9604936
Cdc25 phosphatases activate the cell division kinases throughout the cell cycle. The 2.3 A structure of the human Cdc25A catalytic domain reveals a small alpha/beta domain with a fold unlike previously described phosphatase structures but identical to rhodanese, a sulfur-transfer protein. Only the active-site loop, containing the Cys-(X)5-Arg motif, shows similarity to the tyrosine phosphatases. In some crystals, the catalytic Cys-430 forms a disulfide bond with the invariant Cys-384, suggesting that Cdc25 may be self-inhibited during oxidative stress. Asp-383, previously proposed to be the general acid, instead serves a structural role, forming a conserved buried salt-bridge. We propose that Glu-431 may act as a general acid. Structure-based alignments suggest that the noncatalytic domain of the MAP kinase phosphatases will share this topology, as will ACR2, a eukaryotic arsenical resistance protein.
Figure 2.
Figure 2. Ribbon Drawing of the Catalytic Domain of Human Cdc25AThe CH2A, active site, and CH2B motifs are indicated in green, red, and blue, respectively. The side chain of the Cys-430 nucleophile is shown in yellow. The N terminus (residue 335) is indicated on the left (N), while the C terminus extends toward the viewer and is clipped in this figure. Figure created with MOLSCRIPT ([31]) and the ray-tracing program VORT (University of Melbourne).
Figure 5.
Figure 5. The Active Site of Cdc25A(A) Ball-and-stick model.(B) CPK model, in the same orientation, with a molecular surface ([37]) in gold. Unlabeled residues are gray; all others are colored according to chemical property. The C-terminal tail of Cdc25A can be seen behind the active site, extending away from the protein. Graphics rendered with O ( [29]) and VORT (University of Melbourne).
The above figures are reprinted by permission from Cell Press: Cell (1998, 93, 617-625) copyright 1998.
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