EMD-1438

Single-particle
19.0 Å
EMD-1438 Deposition: 03/10/2007
Map released: 03/10/2007
Last modified: 31/10/2012
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
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EMD-1438

Architecture of the yeast Rrp44 exosome complex suggests routes of RNA recruitment for 3' end processing.

EMD-1438

Single-particle
19.0 Å
EMD-1438 Deposition: 03/10/2007
Map released: 03/10/2007
Last modified: 31/10/2012
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Saccharomyces cerevisiae
Sample: Rrp44-associated exosome complex

Deposition Authors: Wang H-W, Wang J, Ding F, Callahan K, Bratkowski MA, Butler JS, Nogales E, Ke A
Architecture of the yeast Rrp44 exosome complex suggests routes of RNA recruitment for 3' end processing.
Wang HW, Wang J, Ding F, Callahan K, Bratkowski MA, Butler JS, Nogales E, Ke A
(2007) PNAS , 104 , 16844 - 16849
Abstract:
The eukaryotic core exosome (CE) is a conserved nine-subunit protein complex important for 3' end trimming and degradation of RNA. In yeast, the Rrp44 protein constitutively associates with the CE and provides the sole source of processive 3'-to-5' exoribonuclease activity. Here we present EM reconstructions of the core and Rrp44-bound exosome complexes. The two-lobed Rrp44 protein binds to the RNase PH domain side of the exosome and buttresses the bottom of the exosome-processing chamber. The Rrp44 C-terminal body part containing an RNase II-type active site is anchored to the exosome through a conserved set of interactions mainly to the Rrp45 and Rrp43 subunit, whereas the Rrp44 N-terminal head part is anchored to the Rrp41 subunit and may function as a roadblock to restrict access of RNA to the active site in the body region. The Rrp44-exosome (RE) architecture suggests an active site sequestration mechanism for strict control of 3' exoribonuclease activity in the RE complex.