4p82
From Proteopedia
Structure of PyrR protein from Bacillus subtilis
Structural highlights
FunctionPYRR_BACSU Regulates transcriptional attenuation of the pyrimidine nucleotide (pyr) operon by binding in a uridine-dependent manner to specific sites on pyr mRNA. This disrupts an antiterminator hairpin in the RNA and favors formation of a downstream transcription terminator, leading to a reduced expression of downstream genes.[HAMAP-Rule:MF_01219] Also displays a weak uracil phosphoribosyltransferase activity which is not physiologically significant.[HAMAP-Rule:MF_01219] Publication Abstract from PubMedEvolution and design of protein complexes are almost always viewed through the lens of amino acid mutations at protein interfaces. We showed previously that residues not involved in the physical interaction between proteins make important contributions to oligomerization by acting indirectly or allosterically. In this work, we sought to investigate the mechanism by which allosteric mutations act, using the example of the PyrR family of pyrimidine operon attenuators. In this family, a perfectly sequence-conserved helix that forms a tetrameric interface is exposed as solvent-accessible surface in dimeric orthologs. This means that mutations must be acting from a distance to destabilize the interface. We identified 11 key mutations controlling oligomeric state, all distant from the interfaces and outside ligand-binding pockets. Finally, we show that the key mutations introduce conformational changes equivalent to the conformational shift between the free versus nucleotide-bound conformations of the proteins. Evolution of oligomeric state through allosteric pathways that mimic ligand binding.,Perica T, Kondo Y, Tiwari SP, McLaughlin SH, Kemplen KR, Zhang X, Steward A, Reuter N, Clarke J, Teichmann SA Science. 2014 Dec 19;346(6216):1254346. doi: 10.1126/science.1254346. PMID:25525255[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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