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Publication Abstract from PubMed

BACKGROUND: The exosome complex is an essential RNA 3'-end processing and degradation machinery. In archaeal organisms, the exosome consists of a catalytic ring and an RNA-binding ring, both of which were previously reported to assume three-fold symmetry. METHODOLOGY/PRINCIPAL FINDINGS: Here we report an asymmetric 2.9 A Sulfolobus solfataricus archaeal exosome structure in which the three-fold symmetry is broken due to combined rigid body and thermal motions mainly within the RNA-binding ring. Since increased conformational flexibility was also observed in the RNA-binding ring of the related bacterial PNPase, we speculate that this may reflect an evolutionarily conserved mechanism to accommodate diverse RNA substrates for degradation. CONCLUSION/SIGNIFICANCE: This study clearly shows the dynamic structures within the RNA-binding domains, which provides additional insights on mechanism of asymmetric RNA binding and processing.

Crystal structure of the S. solfataricus archaeal exosome reveals conformational flexibility in the RNA-binding ring.,Lu C, Ding F, Ke A PLoS One. 2010 Jan 15;5(1):e8739. PMID:20090900^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.