Linked Life Data

16421448

Source:http://linkedlifedata.com/resource/pubmed/id/16421448

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 2
pubmed:dateCreated
2006-1-19
pubmed:abstractText
The X-ray crystal structure of the previously unknown bacteriophage P22 lysozyme, the product of gene 19, has been determined ab initio by direct methods using the program SIR2002. The presence of several partially occupied iodine anions and samarium cations augmented the ability of direct methods to locate all 2268 non-H protein atoms in the asymmetric unit, making this one of the largest structures to date to be determined ab initio. The iodides were introduced from a quick soak, which the crystal survived sufficiently well to diffract to 1.04 angstroms resolution. The complete heavy-atom substructure contributed 6.6% of the total scattering power. The initial determination of the structure assumed that there were two iodide ions in the asymmetric unit, although it was later determined that these sites correspond to partially occupied samarium ions. Tests suggested that it is better to overestimate rather than underestimate the heavy-atom content. While experimental phases from all of the successful tests were of high quality, the best results came from a SAD experiment using the programs SHELXD and SHELXE. Nonetheless, ab initio structure determination by direct methods was found to be a viable alternative to traditional protein crystallographic methods provided that the X-ray data extend to atomic resolution and heavy atoms with sufficient scattering power are present in the crystal.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0907-4449
pubmed:author
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
165-76
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Extension to 2268 atoms of direct methods in the ab initio determination of the unknown structure of bacteriophage P22 lysozyme.
pubmed:affiliation
Institute of Molecular Biology, Howard Hughes Medical Institute and Department of Physics, 1229 University of Oregon, Eugene, OR 97403-1229, USA. blaine@uoxray.uoregon.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural