PDBsum entry 5ivl

Hydrolase

PDB id: 5ivl

Contents

Protein chains

413 a.a.

Ligands

SO4 ×4

Waters ×209

PDB id:

5ivl

Name:

Hydrolase

Title:

Csha helicase

Structure:

Dead-box atp-dependent RNA helicase csha. Chain: b, a. Fragment: unp residues 1-422. Engineered: yes

Source:

Geobacillus stearothermophilus 10. Organism_taxid: 272567. Gene: csha, gt50_10605. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.30Å R-factor: 0.205 R-free: 0.251

Authors:

J.Huen,C.-L.Lin,W.-L.Yi,C.-L.Li,H.Yuan

Key ref:

J.Huen et al. (2017). Structural Insights into a Unique Dimeric DEAD-Box Helicase CshA that Promotes RNA Decay. Structure, 25, 469-481. PubMed id: 28238534 DOI: 10.1016/j.str.2017.01.012

Date:

21-Mar-16 Release date: 22-Mar-17

Protein chains

A0A0K2H973  () -

Enzyme reactions

• Enzyme class: E.C.3.6.4.13 - Rna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1016/j.str.2017.01.012

Structure 25:469-481 (2017)

PubMed id: 28238534

Structural Insights into a Unique Dimeric DEAD-Box Helicase CshA that Promotes RNA Decay.

J.Huen, C.L.Lin, B.Golzarroshan, W.L.Yi, W.Z.Yang, H.S.Yuan.

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.