1UUS

Structure of an activated Dictyostelium STAT in its DNA-unbound form

Summary for 1UUS

• Entry DOI: 10.2210/pdb1uus/pdb
• Related: 1UUR
• Descriptor: STAT PROTEIN (2 entities in total)
• Functional Keywords: dictyostelium, stat, sh2, signal transduction, transducer, transcription factor
• Biological source: DICTYOSTELIUM DISCOIDEUM (SLIME MOLD)
• Total number of polymer chains: 1
• Total formula weight: 53376.73

Authors

Soler-Lopez, M.,Petosa, C.,Fukuzawa, M.,Ravelli, R.,Williams, J.G.,Muller, C.W. (deposition date: 2004-01-09, release date: 2004-03-26, Last modification date: 2024-11-06)

Primary citation

Soler-Lopez, M.,Petosa, C.,Fukuzawa, M.,Ravelli, R.,Williams, J.G.,Muller, C.W.
Structure of an Activated Dictyostelium Stat in its DNA-Unbound Form
Mol.Cell, 13:791-, 2004

PubMed Abstract: 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.

PubMed: 15053873
DOI: 10.1016/S1097-2765(04)00130-3

Experimental method

X-RAY DIFFRACTION (2.8 Å)