The characterisation of aspects related to the single stranded RNA binding ability of African horsesickness virus nonstructural protein NS2
type: CreativeWork
description: African horsesickness virus (AHSV) is a member of the Orbivirus genus and part of the family Reoviridae. It is a double stranded RNA virus with ten genome segments that encode seven structural and four nonstructural proteins. AHSV nonstructural protein NS2, encoded by segment eight, is a single stranded RNA (ssRNA) binding protein. The formation of viral inclusion bodies (VIBs) as well as the selection and condensation of the ten different virus genome segments during encapsidation, are proposed functions of NS2. This study investigates the binding ability of NS2 to ssRNA by looking at the protein structure, as well as its affinity for virus specific mRNAs. NS2 has an α-helix rich C-terminal region and α-helixes are known to be involved in ssRNA binding. BTV NS2 has an α-helix content of 69% and AHSV NS2 an α-helix content of 47%. AHSV NS2 has a lower binding affinity for ssRNA than bluetongue virus (BTV) NS2. There thus seems to be a correlation between the α-helix content of different NS2 proteins and their ssRNA affinity. In order to determine if the difference between the ability of AHSV NS2 and BTV NS2 to bind nonspecifically to poly(U)Agarose can be ascribed to differences in the α-helix rich C-terminal of NS2, a chimeric NS2 protein was constructed that contained the α-helix rich C-terminal of BTV NS2 and the N-terminal of AHSV NS2. The binding affinity of the chimeric NS2 to poly(U)Agarose was compared to that of AHSV NS2 and BTV NS2 and it was found that it correlated well with that of AHSV NS2. The α-helixes therefore do not seem to play a major role in ssRNA binding. The binding affinity of NS2 rather seems to be determined by the N-terminal of the protein. In order to investigate the specific affinity of AHSV NS2 for AHSV mRNAs, it was necessary to obtain mRNA transcripts with terminal ends identical to AHSV mRNAs. The AHSV genes were cloned into a transcription vector with an internal ribozyme. The 3' ends of the transcripts were generated by autolytic …
abstract: African horsesickness virus (AHSV) is a member of the Orbivirus genus and part of the family Reoviridae. It is a double stranded RNA virus with ten genome segments that encode seven structural and four nonstructural proteins. AHSV nonstructural protein NS2, encoded by segment eight, is a single stranded RNA (ssRNA) binding protein. The formation of viral inclusion bodies (VIBs) as well as the selection and condensation of the ten different virus genome segments during encapsidation, are proposed functions of NS2. This study investigates the binding ability of NS2 to ssRNA by looking at the protein structure, as well as its affinity for virus specific mRNAs. NS2 has an α-helix rich C-terminal region and α-helixes are known to be involved in ssRNA binding. BTV NS2 has an α-helix content of 69% and AHSV NS2 an α-helix content of 47%. AHSV NS2 has a lower binding affinity for ssRNA than bluetongue virus (BTV) NS2. There thus seems to be a correlation between the α-helix content of different NS2 proteins and their ssRNA affinity. In order to determine if the difference between the ability of AHSV NS2 and BTV NS2 to bind nonspecifically to poly(U)Agarose can be ascribed to differences in the α-helix rich C-terminal of NS2, a chimeric NS2 protein was constructed that contained the α-helix rich C-terminal of BTV NS2 and the N-terminal of AHSV NS2. The binding affinity of the chimeric NS2 to poly(U)Agarose was compared to that of AHSV NS2 and BTV NS2 and it was found that it correlated well with that of AHSV NS2. The α-helixes therefore do not seem to play a major role in ssRNA binding. The binding affinity of NS2 rather seems to be determined by the N-terminal of the protein. In order to investigate the specific affinity of AHSV NS2 for AHSV mRNAs, it was necessary to obtain mRNA transcripts with terminal ends identical to AHSV mRNAs. The AHSV genes were cloned into a transcription vector with an internal ribozyme. The 3' ends of the transcripts were generated by autolytic …
keywords: African horse sickness virus genetics, UCTD
date published: 2006-04-07
date modified: 2026-07-24T03:52:21Z
provider: University of Pretoria
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Pretoria

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2263/23560