1ui5: Difference between revisions

[[Image:1ui5.jpg|left|200px]]<br /><applet load="1ui5" size="350" color="white" frame="true" align="right" spinBox="true"  

The gamma-butyrolactone-type autoregulator/receptor systems in the Gram-positive bacterial genus Streptomyces regulate morphological differentiation or antibiotic production, or both. The autoregulator receptors act as DNA-binding proteins, and on binding their cognate ligands (gamma-butyrolactones) they are released from the DNA, thus serving as repressors. The crystal structure of CprB in Streptomyces coelicolor A3(2), a homologue of the A-factor-receptor protein, ArpA, in Streptomyces griseus, was determined. The overall structure of CprB shows that the gamma-butyrolactone receptors belong to the TetR family. CprB is composed of two domains, a DNA-binding domain and a regulatory domain. The regulatory domain contains a hydrophobic cavity, which probably serves as a ligand-binding pocket. On the basis of the crystal structure of CprB and on the analogy of the characteristics of ligand-TetR binding, the binding of gamma-butyrolactones to the regulatory domain of the receptors is supposed to induce the relocation of the DNA-binding domain through conformational changes of residues located between the ligand-binding site and the DNA-binding domain, which would result in the dissociation of the receptors from their target DNA.

1UI5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_coelicolor Streptomyces coelicolor]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1UI5 OCA].  

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