Primary Citation of Related Structures: 1ECS, 1EWJ
PubMed Abstract:
The transposon Tn5 carries a gene designated ble that confers resistance to bleomycin (Bm). In this study, we determined the x-ray crystal structures of the ble gene product, designated BLMT, uncomplexed and complexed with Bm at 1.7 and 2.5 A resolution, respectively ...
The transposon Tn5 carries a gene designated ble that confers resistance to bleomycin (Bm). In this study, we determined the x-ray crystal structures of the ble gene product, designated BLMT, uncomplexed and complexed with Bm at 1.7 and 2.5 A resolution, respectively. The structure of BLMT is a dimer with two Bm-binding pockets composed of two large concavities and two long grooves. This crystal structure of BLMT complexed with Bm gives a precise mode for binding of the antibiotic to BLMT. The conformational change of BLMT generated by binding to Bm occurs at a beta-turn composed of the residues from Gln(97) to Thr(102). Crystallographic analysis of Bm bound to BLMT shows that two thiazolium rings of the bithiazole moiety are in the trans conformation. The axial ligand, which binds a metal ion, seems to be the primary amine in the beta-aminoalanine moiety. This report, which is the first with regard to the x-ray crystal structure of Bm, shows that the bithiazole moiety of Bm is far from the metal-binding domain. That is, Bm complexed with BLMT takes a more extended form than the drug complexed with DNA.
Related Citations:
Characterizaton of the bleomycin resistance determinant encoded on the transposon Tn5 Kumagai, T., Nakano, T., Maruyama, M., Mochizuki, H., Sugiyama, M. (1999) FEBS Lett 442: 34
Crystallization and preliminary X-ray diffraction studies of bleomycin-binding protein encoded on the transposon Tn5 Kumagai, T., Maruyama, M., Matoba, Y., Kawano, Y., Sugiyama, M. (1999) Acta Crystallogr D Biol Crystallogr 55: 1095
Organizational Affiliation:
Institute of Pharmaceutical Sciences, Faculty of Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Japan.
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