5IVL

CshA Helicase

Summary for 5IVL

• Entry DOI: 10.2210/pdb5ivl/pdb
• Descriptor: DEAD-box ATP-dependent RNA helicase CshA, SULFATE ION (3 entities in total)
• Functional Keywords: rec-a like domain dead-box helicase, hydrolase
• Biological source: Geobacillus stearothermophilus 10
• Cellular location: Cytoplasm : A0A0K2H973
• Total number of polymer chains: 2
• Total formula weight: 97125.92

Authors

Huen, J.,Lin, C.-L.,Yi, W.-L.,Li, C.-L.,Yuan, H. (deposition date: 2016-03-21, release date: 2017-03-22, Last modification date: 2023-11-08)

Primary citation

Huen, J.,Lin, C.-L.,Golzarroshan, B.,Yi, W.-L.,Yang, W.Z.,Yuan, H.S.
Structural Insights into a Unique Dimeric DEAD-Box Helicase CshA that Promotes RNA Decay.
Structure, 25:469-481, 2017

PubMed Abstract: CshA is a dimeric DEAD-box helicase that cooperates with ribonucleases for mRNA turnover. The molecular mechanism for how a dimeric DEAD-box helicase aids in RNA decay remains unknown. Here, we report the crystal structure and small-angle X-ray scattering solution structure of the CshA from Geobacillus stearothermophilus. In contrast to typical monomeric DEAD-box helicases, CshA is exclusively a dimeric protein with the RecA-like domains of each protomer forming a V-shaped structure. We show that the C-terminal domains protruding outward from the tip of the V-shaped structure is critical for mediating strong RNA binding and is crucial for efficient RNA-dependent ATP hydrolysis. We also show that RNA remains bound with CshA during ATP hydrolysis cycles and thus bulk RNAs could be unwound and degraded in a processive manner through cooperation between exoribonucleases and CshA. A dimeric helicase is hence preserved in RNA-degrading machinery for efficient RNA turnover in prokaryotes and eukaryotes.

PubMed: 28238534
DOI: 10.1016/j.str.2017.01.012

Experimental method

X-RAY DIFFRACTION (2.3 Å)