3WZI

Crystal structure of AfCsx3 in complex with ssRNA

Summary for 3WZI

• Entry DOI: 10.2210/pdb3wzi/pdb
• Related: 3WZG 3WZH
• Descriptor: Uncharacterized protein AF_1864, ssRNA (3 entities in total)
• Functional Keywords: exonuclease, deadenylation activity, transcription-rna complex, transcription/rna
• Biological source: Archaeoglobus fulgidus DSM 4304; More
• Total number of polymer chains: 3
• Total formula weight: 26139.87

Authors

Yuan, Y.A.,Yan, X. (deposition date: 2014-09-25, release date: 2015-07-15, Last modification date: 2024-05-29)

Primary citation

Yan, X.,Guo, W.,Yuan, Y.A.
Crystal structures of CRISPR-associated Csx3 reveal a manganese-dependent deadenylation exoribonuclease.
Rna Biol., 12:749-760, 2015

PubMed Abstract: In prokaryotes, the CRISPR/Cas system is known to target and degrade invading phages and foreign genetic elements upon subsequent infection. However, the structure and function of many Cas proteins remain largely unknown, due to the high diversity of Cas proteins. Here we report 3 crystal structures of Archaeoglobus fulgidus Csx3 (AfCsx3) in free form, in complex with manganese ions and in complex with a single-stranded RNA (ssRNA) fragment, respectively. AfCsx3 harbors a ferredoxin-like fold and forms dimer both in the crystal and in solution. Our structure-based biochemical analysis demonstrates that the RNA binding sites and cleavage sites are located at 2 separate surfaces within the AfCsx3 dimer, suggesting a model to bind, tether and cleave the incoming RNA substrate. In addition, AfCsx3 displays robust 3'-deadenylase activity in the presence of manganese ions, which strongly suggests that AfCsx3 functions as a deadenylation exonuclease. Taken together, our results indicate that AfCsx3 is a Cas protein involved in RNA deadenylation and provide a framework for understanding the role of AfCsx3 in the Type III-B CRISPR/Cas system.

PubMed: 26106927
DOI: 10.1080/15476286.2015.1051300

Experimental method

X-RAY DIFFRACTION (2.9 Å)