Dataset Information

How baculovirus polyhedra fit square pegs into round holes to robustly package viruses.

ABSTRACT: Natural protein crystals (polyhedra) armour certain viruses, allowing them to survive for years under hostile conditions. We have determined the structure of polyhedra of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), revealing a highly symmetrical covalently cross-braced robust lattice, the subunits of which possess a flexible adaptor enabling this supra-molecular assembly to specifically entrap massive baculoviruses. Inter-subunit chemical switches modulate the controlled release of virus particles in the unusual high pH environment of the target insect's gut. Surprisingly, the polyhedrin subunits are more similar to picornavirus coat proteins than to the polyhedrin of cytoplasmic polyhedrosis virus (CPV). It is, therefore, remarkable that both AcMNPV and CPV polyhedra possess identical crystal lattices and crystal symmetry. This crystalline arrangement must be particularly well suited to the functional requirements of the polyhedra and has been either preserved or re-selected during evolution. The use of flexible adaptors to generate a powerful system for packaging irregular particles is characteristic of the AcMNPV polyhedrin and may provide a vehicle to sequester a wide range of objects such as biological nano-particles.

SUBMITTER: Ji X

PROVIDER: S-EPMC2824454 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

How baculovirus polyhedra fit square pegs into round holes to robustly package viruses.

Ji Xiaoyun X Sutton Geoff G Evans Gwyndaf G Axford Danny D Owen Robin R Stuart David I DI

The EMBO journal 20091203 2

Natural protein crystals (polyhedra) armour certain viruses, allowing them to survive for years under hostile conditions. We have determined the structure of polyhedra of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), revealing a highly symmetrical covalently cross-braced robust lattice, the subunits of which possess a flexible adaptor enabling this supra-molecular assembly to specifically entrap massive baculoviruses. Inter-subunit chemical switches modulate the ...[more]

PMID: 19959989

Similar Datasets

Project description:ObjectivePediatric emergency medicine (PEM) fellowship directors can interview candidates from either pediatric or EM residency programs. Currently, most candidates are pediatricians; however, because emergency physicians have attributes that could benefit PEM, our goal was to investigate facilitators and barriers to training more of them to become PEM physicians.MethodsWe surveyed U.S. PEM fellowship program directors (PDs) about their program's recruitment practices: Do they recruit only pediatricians or mostly pediatricians with an occasional emergency physician or do they actively recruit both? We solicited volunteers from each recruitment group for interviews. These were recorded, transcribed, and thematically coded using summative content analysis. Comments were cataloged into themes that were philosophical or logistic in nature and those that might facilitate (drivers) or serve as barriers (restrainers) to the inclusion of emergency physicians in PEM.ResultsWe received 50 of 86 (58%) survey responses, 29 (34%) of whom volunteered for interviews. The 17 volunteers we selected for interviews generated 13 themes that fell into the four major theme categories: four philosophical drivers, three logistic drivers, two philosophical restrainers, and four logistic restrainers. Program groups differed with regard to the inclusion of emergency physicians. Most limiting were the impact of variable program length and the implicit belief that pediatricians are best suited to treat children. Most beneficial is the recognized value of EM graduates to the field of PEM.ConclusionsWhile PDs acknowledged a growing need for PEM physicians, particularly in community hospitals, and that emergency physicians would contribute to PEM, they also identified the logistical burden of including them in programs primarily designed for pediatricians. This burden involves maintaining separate curricula for EM graduates and finding emergency physician faculty to serve as mentors. PDs also expressed a desire for resources to guide the integration of more emergency physicians into their programs.

Project description:We have determined the nucleotide sequences of a highly conserved region of the RNA-dependent RNA polymerase of the prototype Snow Mountain agent (SMA) and of four other small, round-structured viruses (antigenically Norwalk virus [NV]-like or SMA-like) following reverse transcription-PCR amplification of viral RNA obtained from human stools. The stool samples were either from volunteers administered SMA or from sporadic cases and outbreaks of gastroenteritis that occurred in Japan and the United Kingdom between 1984 and 1992. The GLPSG and YGDD RNA polymerase motifs were in the proper locations in the sequences of the five SRSVs, but each sequence was distinct from the 8FIIa prototype NV sequence and from each other. Analysis of the sequences and reactivities in a new NV antigen enzyme-linked immunosorbent assay showed that the five viruses could be divided into two groups (serogroups) with NV and SMA, respectively, being the prototypes. The sequences of the capsid region and a nonstructural region (2C) were determined from one strain from each group. One virus (SRSV-KY-89/89/J), isolated in Japan and antigenically similar to the prototype NV (isolated 21 years earlier in Ohio), showed a remarkable level of sequence similarity to NV. KY-89 and the 8FIIa NV showed 87.2% nucleotide similarity over 2,516 continuous nucleotides amounting to 96 to 98.9% amino acid similarity in three distinct domains in two open reading frames. Between the prototype SMA and NV, the polymerase region showed 63% nucleotide and 59% amino acid similarity, respectively. Two other antigenically SMA-like isolates (SRSV-925/92/UK and SRSV-OTH-25/89/J), from the United Kingdom and Japan, showed 80% nucleotide and 88 to 92% amino acid similarity in the polymerase region to the prototype SMA isolated 16 and 13 years earlier in the United States. The capsid region of the antigenically SMA-like OTH-25 virus showed 53% nucleotide and 65% amino acid similarity to the prototype NV capsid region. Domains of sequence diversity and conversation were identified within the capsid protein of these two distinct prototype serotypes of virus. These results indicate that NV-like and SMA-like agents are still circulating, and sequence comparisons will be useful to identify and classify distinct viruses in the NV group.

Dataset Information

How baculovirus polyhedra fit square pegs into round holes to robustly package viruses.

Publications

How baculovirus polyhedra fit square pegs into round holes to robustly package viruses.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets