PDBsum entry 6bb8

RNA binding protein

PDB id: 6bb8

Contents

Protein chain

927 a.a.

PDB id:

6bb8

Name:

RNA binding protein

Title:

Crystal structure of frequency-interacting RNA helicase (frh)

Structure:

Frq-interacting RNA helicase. Chain: a. Synonym: probable atp dependent RNA helicase. Engineered: yes

Source:

Neurospora crassa. Organism_taxid: 5141. Gene: b9b11.040, frh, ncu03363.1. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

3.49Å R-factor: 0.253 R-free: 0.301

Authors:

Y.Morales,S.J.Johnson,K.J.Olsen

Key ref:

Y.Morales et al. (2018). Structure of frequency-interacting RNA helicase from Neurospora crassa reveals high flexibility in a domain critical for circadian rhythm and RNA surveillance. PLoS One, 13, e0196642. PubMed id: 29718972

Date:

17-Oct-17 Release date: 29-Aug-18

Protein chain

Q1K502  (Q1K502_NEUCR) -  FRQ-interacting RNA helicase from Neurospora crassa (strain ATCC 24698 / 74-OR23-1A / CBS 708.71 / DSM 1257 / FGSC 987)

Seq: 1106 a.a.

Struc: 927 a.a.

PLoS One 13:e0196642 (2018)

PubMed id: 29718972

Structure of frequency-interacting RNA helicase from Neurospora crassa reveals high flexibility in a domain critical for circadian rhythm and RNA surveillance.

Y.Morales, K.J.Olsen, J.M.Bulcher, S.J.Johnson.

ABSTRACT

The FRH (frequency-interacting RNA helicase) protein is the Neurospora crassa homolog of yeast Mtr4, an essential RNA helicase that plays a central role in RNA metabolism as an activator of the nuclear RNA exosome. FRH is also a required component of the circadian clock, mediating protein interactions that result in the rhythmic repression of gene expression. Here we show that FRH unwinds RNA substrates in vitro with a kinetic profile similar to Mtr4, indicating that while FRH has acquired additional functionality, its core helicase function remains intact. In contrast with the earlier FRH structures, a new crystal form of FRH results in an ATP binding site that is undisturbed by crystal contacts and adopts a conformation consistent with nucleotide binding and hydrolysis. Strikingly, this new FRH structure adopts an arch domain conformation that is dramatically altered from previous structures. Comparison of the existing FRH structures reveals conserved hinge points that appear to facilitate arch motion. Regions in the arch have been previously shown to mediate a variety of protein-protein interactions critical for RNA surveillance and circadian clock functions. The conformational changes highlighted in the FRH structures provide a platform for investigating the relationship between arch dynamics and Mtr4/FRH function.