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Isolation, crystallization and X‐ray analysis of the quaternary complex of Phe‐tRNA Phe , EF‐Tu, a GTP analog and kirromycin
Author(s) -
Kristensen Ole,
Reshetnikova Ludmila,
Nissen Poul,
Siboska Gunhild,
Thirup Søren,
Nyborg Jens
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(96)01281-1
Subject(s) - thermus thermophilus , crystallography , crystallization , ternary complex , ef tu , chemistry , escherichia coli , gtp' , crystal structure , stereochemistry , transfer rna , thermophile , biochemistry , enzyme , rna , organic chemistry , gene
Kirromycin inhibits bacterial protein synthesis by acting on elongation factor Tu (EF‐Tu). Complexes of the antibiotic, Phe‐tRNA Phe , the guanosine triphosphate analog GDPNP, and mesophilic ( Escherichia coli ), as well as thermophilic ( Thermus thermophilus ) EF‐Tu were isolated. Crystallization was achieved at 4°C, pH 6.4, using ammonium sulphate as precipitant. Crystallographic data were recorded at cryogenic temperature on crystals exposed to synchrotron radiation. Crystals of the thermophilic complex are based on a rhombohedral lattice with cell dimensions of 137.3 Å, and angles of 54.0°. Although related, these cell parameters are different from those found in the crystals of the recently solved structure of the ternary complex of Phe‐tRNA Phe , GDPNP, and Thermus aquaticus EF‐Tu (Nissen, P., Kjeldgaard, M., Thirup, S., Polekhina, G., Reshetnikova, L., Clark, B.F. and Nyborg, J. (1995) Science 270, 1464–1472 [1]), possibly indicating some allosteric effect caused by kirromycin. Crystals of the mesophilic complex belong to the cubic space P432, with cell axis of 196.26 Å. In both cases, the crystals contain one complex per asymmetric unit.