Significance of EGFR/HER2 Expression and PIK3CA Mutations in Giant Cell Tumour of Bone Development

Figure 3

Missense mutation, c.1634A>C encoding p.E545A, in exon 9 of PIK3CA gene. (a) Sequence chromatograms from affected patient with the c.1634A>C mutation in PIK3CA gene. (b) Sequence alignment of the PIK3CA protein in different species performed by the ClustalW program showing the conservation of the residue Glutamic acid (E) at position 545. (c) Interaction between the catalytic subunit p110 of PI 3-kinase and the niSH2 domain of the regulatory p85 subunit (pdb code 4L23). (i) Overall cartoon structure of the complex, (ii) zoom of the amino acid E545 (red sticks) and its ionic interactions (in orange discontinued line) with K548 of P110 and K379 of p85 subunit (nSH2 domain), and (iii) E545A mutant showing A545 interacting with L380 of the regulatory subunit.

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