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1uus
From Proteopedia
STRUCTURE OF AN ACTIVATED DICTYOSTELIUM STAT IN ITS DNA-UNBOUND FORM
Overview
Dd-STATa is a STAT protein which transcriptionally regulates cellular differentiation in Dictyostelium discoideum, the only non-metazoan known to employ SH2 domain signaling. The 2.7 A crystal structure of a tyrosine phosphorylated Dd-STATa homodimer reveals a four-domain architecture similar to that of mammalian STATs 1 and 3, but with an inverted orientation for the coiled-coil domain. Dimerization is mediated by SH2 domain:phosphopeptide interactions and by a direct interaction between SH2 domains. The unliganded Dd-STATa dimer adopts a fully extended conformation remarkably different from that of the DNA-bound mammalian STATs, implying a large conformational change upon target site recognition. Buried hydrophilic residues predicted to destabilize the coiled-coil domain suggest how hydrophobic residues may become exposed and mediate nuclear export. Functional and evolutionary implications for metazoan STAT proteins are discussed.
About this Structure
1UUS is a Single protein structure of sequence from Dictyostelium discoideum. Full crystallographic information is available from OCA.
Reference
Structure of an activated Dictyostelium STAT in its DNA-unbound form., Soler-Lopez M, Petosa C, Fukuzawa M, Ravelli R, Williams JG, Muller CW, Mol Cell. 2004 Mar 26;13(6):791-804. PMID:15053873 Page seeded by OCA on Sat May 3 11:43:23 2008
