Lysine residues within the PTP motif: (HCKAGKGR; lysines in bold) along with a His residue within the WPD loop (Lee et al., 1999). Interestingly, the PTP motif of Cdc14 (HCKAGLGR) is also reminiscent of PTEN, even though the His residue on the WPD loop of PTEN is often a glycine (Gly288) in Cdc14, and as a result it really is unlikely that Cdc14 functions to dephosphorylate lipid substrates. TheC.H.Gray et al.Fig. 3. Cyprodime Antagonist structural relatedness of your A and Bdomains of Cdc14B. (A) Comparison of structures in the A and Bdomains of Cdc14B plus the phosphatase domain of PTEN. In the upper panel, the three domains are shown in the exact same orientation, and a stereoview of the Adomain (green) and Bdomain (blue) superimposed is shown within the reduce panel. (B) Structurebased sequence alignment of domains A and B of Cdc14B. Equivalent secondary structural elements are suf ed with `A’ and `B’ for domains A and B, respectively.most closely related protein phosphatases to Cdc14 are kinaseassociated phosphatase (KAP) (Song et al., 2001) and vaccinia H1related phosphatase (VHR) (Yuvaniyama et al., 1996) (Table II).The Adomain features a DSPlike foldThe 3D architecture on the Adomain (residues 4498) bears a exceptional resemblance towards the Bdomain of Cdc14. As shown in Figure 3A, the secondary structural components of the Adomain superimpose closely onto the conserved core components of the Bdomain, and also the two domains share the identical secondary structure topology andpolypeptide connectivities. All round, the Ca atoms of 119 equivalent residues superimpose inside an r.m.s.d. of 2.6 A and also the Zscore, a measure with the structural similarity in standard deviations above the expected worth between two molecules, is 9.6 (Table II). Interestingly, this evaluation indicated that the PTP/DSP family members is structurally exclusive, such that a equivalent topology doesn’t take place in other proteins. These dings suggest that the Adomain of Cdc14 resulted from divergent evolution from an ancestral PTP/DSP family members member, possibly from a gene duplication event of the existing catalytically active Bdomain.Cdc14B isn’t re cted in any sequence similarity. A structurebased alignment on the A and Bdomains indicates only 11 sequence identity (Figure 3B). Importantly, none on the catalytic web-site residues, which includes the catalytic site Cys and Arg residues, characteristic of PTP/DSPs, is present in the Adomain. Signi antly, the structure from the Adomain suggests that it will be unable to bind phosphate within the equivalent area of your molecule towards the phosphatebinding cradle formed by the PTP signature motif on the Bdomain. Inside the Adomain, an insertion of two residues at the Nterminus of a4A, equivalent towards the a4B helix which types the base in the catalytic website inside the Bdomain (Figure 3B), alters the conformation from the Adomain so that it no longer types a phosphatebinding cradle. Consistent with all the notion that the Adomain is incapable of binding a phosphate moiety, we observed tungstate at 25 mM bound only towards the catalytic web site of your Bdomain. Other variations among the A and Bdomains include things like a 13 residue insertion within the a5A/a6A loop, which contributes for the peptidebinding groove, plus the counterpart to the WPD loop with the Bdomain is four residues longer in the Adomain (Figure 3B). Ultimately, you will find no equivalents on the a1 and a2 helices, and b4 strand, conserved inside the Bdomain of Cdc14B and other DSPs.The peptidebinding groove is selective for prolinedirected peptidesA one of a kind feature on the catalytic internet site of Cdc14B is its location withi.
