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Title: Preliminary crystallographic analysis of avian infectious bronchitis virus main protease

Abstract

The avian infectious bronchitis virus main protease has been crystallized; crystals diffract to 2.7 Å resolution. Infectious bronchitis virus (IBV) is the prototype of the genus Coronavirus. It causes a highly contagious disease which affects the respiratory, reproductive, neurological and renal systems of chickens, resulting great economic losses in the poultry industry worldwide. The coronavirus (CoV) main protease (M{sup pro}), which plays a pivotal role in viral gene expression and replication through a highly complex cascade involving the proteolytic processing of replicase polyproteins, is an attractive target for antiviral drug design. In this study, IBV M{sup pro} was overexpressed in Escherichia coli. Crystals suitable for X-ray crystallography have been obtained using microseeding techniques and belong to space group P6{sub 1}22. X-ray diffraction data were collected in-house to 2.7 Å resolution from a single crystal. The unit-cell parameters were a = b = 119.1, c = 270.7 Å, α = β = 90, γ = 120°. Three molecules were predicted to be present in the asymmetric unit from a calculated self-rotation function.

Authors:
;  [1];  [2];  [1];  [3]
  1. Laboratory of Structural Biology, Tsinghua University, Beijing 100084 (China)
  2. Laboratory of Avian Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642 (China)
  3. (China)
Publication Date:
OSTI Identifier:
22360254
Resource Type:
Journal Article
Resource Relation:
Journal Name: Acta Crystallographica. Section F; Journal Volume: 63; Journal Issue: Pt 1; Other Information: PMCID: PMC2330114; PMID: 17183167; PUBLISHER-ID: pu5171; OAI: oai:pubmedcentral.nih.gov:2330114; Copyright (c) International Union of Crystallography 2007; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United Kingdom
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CRYSTALLOGRAPHY; DESIGN; ESCHERICHIA COLI; LOSSES; MOLECULES; MONOCRYSTALS; PROCESSING; RESOLUTION; ROTATION; SPACE GROUPS; X-RAY DIFFRACTION

Citation Formats

Li, Jun, Shen, Wei, Liao, Ming, E-mail: mliao@scau.edu.cn, Bartlam, Mark, E-mail: mliao@scau.edu.cn, and National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101. Preliminary crystallographic analysis of avian infectious bronchitis virus main protease. United Kingdom: N. p., 2007. Web. doi:10.1107/S1744309106052341.
Li, Jun, Shen, Wei, Liao, Ming, E-mail: mliao@scau.edu.cn, Bartlam, Mark, E-mail: mliao@scau.edu.cn, & National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101. Preliminary crystallographic analysis of avian infectious bronchitis virus main protease. United Kingdom. doi:10.1107/S1744309106052341.
Li, Jun, Shen, Wei, Liao, Ming, E-mail: mliao@scau.edu.cn, Bartlam, Mark, E-mail: mliao@scau.edu.cn, and National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101. Mon . "Preliminary crystallographic analysis of avian infectious bronchitis virus main protease". United Kingdom. doi:10.1107/S1744309106052341.
@article{osti_22360254,
title = {Preliminary crystallographic analysis of avian infectious bronchitis virus main protease},
author = {Li, Jun and Shen, Wei and Liao, Ming, E-mail: mliao@scau.edu.cn and Bartlam, Mark, E-mail: mliao@scau.edu.cn and National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101},
abstractNote = {The avian infectious bronchitis virus main protease has been crystallized; crystals diffract to 2.7 Å resolution. Infectious bronchitis virus (IBV) is the prototype of the genus Coronavirus. It causes a highly contagious disease which affects the respiratory, reproductive, neurological and renal systems of chickens, resulting great economic losses in the poultry industry worldwide. The coronavirus (CoV) main protease (M{sup pro}), which plays a pivotal role in viral gene expression and replication through a highly complex cascade involving the proteolytic processing of replicase polyproteins, is an attractive target for antiviral drug design. In this study, IBV M{sup pro} was overexpressed in Escherichia coli. Crystals suitable for X-ray crystallography have been obtained using microseeding techniques and belong to space group P6{sub 1}22. X-ray diffraction data were collected in-house to 2.7 Å resolution from a single crystal. The unit-cell parameters were a = b = 119.1, c = 270.7 Å, α = β = 90, γ = 120°. Three molecules were predicted to be present in the asymmetric unit from a calculated self-rotation function.},
doi = {10.1107/S1744309106052341},
journal = {Acta Crystallographica. Section F},
number = Pt 1,
volume = 63,
place = {United Kingdom},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Various truncated and mutant forms of the protease VP4 from infectious pancreatic necrosis virus were used to generate two different crystal forms of VP4 which diffracted to beyond 2.4 Å resolution. In viruses belonging to the Birnaviridae family, virus protein 4 (VP4) is the viral protease responsible for the proteolytic maturation of the polyprotein encoding the major capsid proteins (VP2 and VP3). Infectious pancreatic necrosis virus (IPNV), the prototype of the aquabirnavirus genus, is the causative agent of a contagious disease in fish which has a large economic impact on aquaculture. IPNV VP4 is a 226-residue (24.0 kDa) serine proteasemore » that utilizes a Ser/Lys catalytic dyad mechanism (Ser633 and Lys674). Several truncated and mutant forms of VP4 were expressed in a recombinant expression system, purified and screened for crystallization. Two different crystal forms diffract beyond 2.4 Å resolution. A triclinic crystal derived from one mutant construct has unit-cell parameters a = 41.7, b = 69.6, c = 191.6 Å, α = 93.0, β = 95.1, γ = 97.7°. A hexagonal crystal with space group P6{sub 1}22/P6{sub 5}22 derived from another mutant construct has unit-cell parameters a = 77.4, b = 77.4, c = 136.9 Å.« less
  • Infection of cells with the avian coronavirus infectious bronchitis virus results in the synthesis of five major subgenomic RNAs. These RNAs and the viral genome form a 3' coterminal nested set. We found that the rates of inactivation of synthesis of the RNAs by UV light were different and increased with the length of the transcript. These results show that each RNA is transcribed from a unique promoter and that extensive processing of the primary transcripts probably does not occur.
  • Because phosphorylation of the infectious bronchitis virus (IBV) nucleocapsid protein (N) may regulate its multiple roles in viral replication, the dynamics of N phosphorylation were examined. {sup 32}P-orthophosphate labeling and Western blot analyses confirmed that N was the only viral protein that was phosphorylated. Pulse labeling with {sup 32}P-orthophosphate indicated that the IBV N protein was phosphorylated in the virion, as well as at all times during infection in either chicken embryo kidney cells or Vero cells. Pulse-chase analyses followed by immunoprecipitation of IBV N proteins using rabbit anti-IBV N polyclonal antibody demonstrated that the phosphate on the N proteinmore » was stable for at least 1 h. Simultaneous labeling with {sup 32}P-orthophosphate and {sup 3}H-leucine identified a 3.5-fold increase in the {sup 32}P:{sup 3}H counts per minute (cpm) ratio of N in the virion as compared to the {sup 32}P:{sup 3}H cpm ratio of N in the cell lysates from chicken embryo kidney cells, whereas in Vero cells the {sup 32}P:{sup 3}H cpm ratio of N from the virion was 10.5-fold greater than the {sup 32}P:{sup 3}H cpm ratio of N from the cell lysates. These studies are consistent with the phosphorylation of the IBV N playing a role in assembly or maturation of the viral particle.« less
  • Crystals of the human immunodeficiency virus 1 subtype C protease complexed with indinavir and nelfinavir have been grown in the monoclinic space group P2{sub 1} and shown to diffract X-rays to 2.3 Å resolution. Crystals of the human immunodeficiency virus 1 (HIV-1) subtype C protease (PR) complexed with the clinically used inhibitors indinavir (IDV) and nelfinavir (NFV) have been grown in the monoclinic space group P2{sub 1}, with mean unit-cell parameters a = 46.7 (±0.1), b = 59.8 (±0.3), c = 87.0 (±0.4) Å, β = 95.2 (±0.5)°. The crystals of both complexes have been shown to diffract X-rays tomore » 2.3 Å resolution. The diffraction data for the subtype C PR complexes with IDV and NFV were subsequently processed and reduced, with overall R{sub sym} values of 8.4 and 11.4%, respectively. Based on the unit-cell volumes, molecular-replacement results and packing considerations, there are two protease homodimers per crystallographic asymmetric unit in each of the complexes. The data were initially phased using a model based on the crystal structure of HIV-1 subtype B PR; the structures have been determined and further refinement and analysis are in progress. These structures and subsequent studies with other inhibitors will greatly aid in correlating the amino-acid variation between the different HIV PRs and understanding their differential sensitivity and resistance to current drug therapy.« less
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