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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1992-10-13
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pubmed:abstractText |
The three-dimensional structure of the heterodimeric alpha 2 beta 2 enzyme phenylalanyl-tRNA synthetase from Thermus thermophilus HB8 has been determined by X-ray crystallography, using the multiple-isomorphous-replacement method at 0.6 nm resolution. Trigonal crystals of space group P3(2)21 have cell dimensions a = b = 17.6 nm and c = 14.2 nm. Assuming one heterodimeric molecule/asymmetric unit, the ratio of unit cell volume/molecular mass was V = 0.00244 nm3/Da, which is in the middle of the range normally observed. However, after a rotation-function calculation and measurement of the density of the native crystals, we postulate the existence of only the alpha beta dimer in the asymmetric units. This implies 73% solvent content in the unit cell. Three heavy-atom derivatives [K2PtCl4, KAu(CN)2 and Hg(CH3COO)2] and the solvent-flattening procedure were used for electron-density-map calculations. This map confirmed our hypothesis and revealed a remarkably large space filled by solvent, with alpha beta dimer only in the asymmetric unit. The phenylalanyl-tRNA synthetase from T. thermophilus molecule has a 'quasi-linear' subunit organization. As can be concluded at this level of resolution, there is no contact between small alpha subunits in the functional heterodimer.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
208
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
411-7
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:1521534-Chemistry, Physical,
pubmed-meshheading:1521534-Crystallization,
pubmed-meshheading:1521534-Fourier Analysis,
pubmed-meshheading:1521534-Macromolecular Substances,
pubmed-meshheading:1521534-Molecular Structure,
pubmed-meshheading:1521534-Molecular Weight,
pubmed-meshheading:1521534-Phenylalanine-tRNA Ligase,
pubmed-meshheading:1521534-Physicochemical Phenomena,
pubmed-meshheading:1521534-Thermus thermophilus,
pubmed-meshheading:1521534-X-Ray Diffraction
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pubmed:year |
1992
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pubmed:articleTitle |
Three-dimensional structure of phenylalanyl-transfer RNA synthetase from Thermus thermophilus HB8 at 0.6-nm resolution.
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pubmed:affiliation |
Institute of Molecular Biology, Academy of Sciences of the USSR, Moscow.
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pubmed:publicationType |
Journal Article
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