Linked Life Data

10860886

Source:http://linkedlifedata.com/resource/pubmed/id/10860886

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-8-2
pubmed:abstractText
T4 encodes two dispensable proteins that bind to the outer surface of the mature capsid. Soc (9 kDa) stabilizes the capsid against extremes of alkaline pH and temperature, but Hoc (40 kDa) has no perceptible effect. Both proteins have been developed as display platforms. Their positions on the hexagonal surface lattice of gp23*, the major capsid protein, were previously defined by two-dimensional image averaging of negatively stained electron micrographs of elongated variant capsids. We have extended these observations by reconstructing cryo-electron micrographs of isometric capsids produced by a point mutant in gene 23, for both Hoc+.Soc+ and Hoc+.Soc- phages. The expected T = 13 lattice was observed, with a single Hoc molecule at the center of each gp23* hexamer. The vertices are occupied by pentamers of gp24*: despite limited sequence similarity with gp23*, the respective monomers are similar in size and shape, suggesting they may have the same fold. However, gp24* binds neither Hoc nor Soc; in situ, Soc is visualized as trimers at the trigonal points of the gp23* lattice and as monomers at the sites closest to the vertices. In solution, Soc is a folded protein ( approximately 10% alpha-helix and 50-60% beta sheet) that is monomeric as determined by analytic ultracentrifugation. Thus its trimerization on the capsid surface is imposed by a template of three symmetry-related binding sites. The observed mode of Soc binding suggests that it stabilizes the capsid by a clamping mechanism and offers a possible explanation for the phenotype of osmotic shock resistance.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0042-6822
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
321-33
pubmed:dateRevised
2004-7-12
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Molecular architecture of bacteriophage T4 capsid: vertex structure and bimodal binding of the stabilizing accessory protein, Soc.
pubmed:affiliation
Laboratory of Structural Biology, National Institutes of Health, Bethesda, MD 20892, USA.
pubmed:publicationType
Journal Article