SASDDT5: Ribonucleoprotein complex of nonstructural protein sigma NS bound...

Basic information

Entry

Database: SASBDB / ID: SASDDT5

Sample

Ribonucleoprotein complex of nonstructural protein sigma NS bound to 20mer RNA (NS-RNP20)

• Nonstructural protein sigma NS (protein), Avian orthoreovirus
• 20mer RNA (unstructured) (RNA), 20mer

• Function / homology: Reovirus non-structural protein sigma NS / Sigma NS protein / single-stranded RNA binding / RNA-dependent RNA polymerase activity / Nonstructural protein sigma NS
• Biological species: Avian orthoreovirus
• Citation: Journal: Nucleic Acids Res / Year: 2018; Title: Stability of local secondary structure determines selectivity of viral RNA chaperones.; Authors: Jack P K Bravo / Alexander Borodavka / Anders Barth / Antonio N Calabrese / Peter Mojzes / Joseph J B Cockburn / Don C Lamb / Roman Tuma / ; Abstract: To maintain genome integrity, segmented double-stranded RNA viruses of the Reoviridae family must accurately select and package a complete set of up to a dozen distinct genomic RNAs. It is thought that the high fidelity segmented genome assembly involves multiple sequence-specific RNA-RNA interactions between single-stranded RNA segment precursors. These are mediated by virus-encoded non-structural proteins with RNA chaperone-like activities, such as rotavirus (RV) NSP2 and avian reovirus σNS. Here, we compared the abilities of NSP2 and σNS to mediate sequence-specific interactions between RV genomic segment precursors. Despite their similar activities, NSP2 successfully promotes inter-segment association, while σNS fails to do so. To understand the mechanisms underlying such selectivity in promoting inter-molecular duplex formation, we compared RNA-binding and helix-unwinding activities of both proteins. We demonstrate that octameric NSP2 binds structured RNAs with high affinity, resulting in efficient intramolecular RNA helix disruption. Hexameric σNS oligomerizes into an octamer that binds two RNAs, yet it exhibits only limited RNA-unwinding activity compared to NSP2. Thus, the formation of intersegment RNA-RNA interactions is governed by both helix-unwinding capacity of the chaperones and stability of RNA structure. We propose that this protein-mediated RNA selection mechanism may underpin the high fidelity assembly of multi-segmented RNA genomes in Reoviridae.

Contact author

• Jack Bravo (University of Leeds)

Models

Sample

• Sample: Name: Ribonucleoprotein complex of nonstructural protein sigma NS bound to 20mer RNA (NS-RNP20); Entity id: 1025 / 1027
• Buffer: Name: 25 mM HEPES, 150 mM NaCl / pH: 7.5

Entity #1025

Type: protein / Description: Nonstructural protein sigma NS / Formula weight: 40.586 / Num. of mol.: 8 / Source: Avian orthoreovirus / References: UniProt: Q9DH28
Sequence:

MDNTVRVGVS RNTSGAAGQT LFRNFYLLRC NISADGRNAT KAVQSHFPFL SRAVRCLSPL AAHCADRTLR RDNVKQILTR ELPFSSDLIN YAHHVNSSSL TTSQGVEAAR LVAQVYGEQV PFDHIYPTGS ATYCPGAIAN AISRIMAGFV PREGDDFAPS GPIDYLAADL IAYKFVLPYM LDMVDGRPQI VLPSHTVEEM LTNTSLLNSI DASFGIEARS DQRMTRDAAE MSSRSLNELE DHDQRGRMPW KIMLAMMAAQ LKVELDALAD ERTESQANAH VTSFGSRLFN QMSAFVTIDR ELMELALLIK EQGFAMNPGQ IASKWSLIRR SGPTRPLSGA RLEIRNGNWM IREGDQTLLS VSPARMA

Entity #1027

Name: 20mer / Type: RNA / Description: 20mer RNA (unstructured) / Formula weight: 6.399 / Num. of mol.: 2
Sequence:

CUUUUCAAGA CAUGCAACAA

Experimental information

• Beam: Instrument name: Diamond Light Source B21 / City: Oxfordshire / 国: UK / Shape: 1 x 5 mm / Type of source: X-ray synchrotron / Wavelength: 0.1 Å / Dist. spec. to detc.: 3.9 mm
• Detector: Name: Pilatus 2M

Scan

Title: Ribonucleoprotein complex of nonstructural protein sigma NS bound to 20mer RNA (NS-RNP20)
Measurement date: Feb 25, 2017 / Unit: 1/A /

	Min	Max
Q	0.0037	0.37

Distance distribution function P(R)

Sofotware P(R): GNOM 5.0 / Number of points: 1040 /

	Min	Max
Q	0.0059053	0.235036
P(R) point	1	1040
R	0	380

Result

Type of curve: merged
Comments: SigmaNS ribonucleoprotein complex with 20mer RNA. Sample concentration, UNKNOWN; Sample temperature, UNKNOWN; Exposure time; UNKNOWN.

	Experimental	Porod
MW	323 kDa	-
Volume	-	964 nm3

	P(R)	Guinier	Guinier error
Forward scattering, I0	0.3067	0.2991	0.001
Radius of gyration, Rg	8.65 nm	7.82 nm	0.06

	Min	Max
D	-	38
Guinier point	11	45