BLMT, a bleomycin resistance protein encoded on the transposon Tn5, and similar proteins
BLMT is a bleomycin (Bm) resistance protein, encoded by the ble gene on the transposon Tn5. This protein confers a survival advantage to Escherichia coli host cells. Bm is a glycopeptide antibiotic produced naturally by actinomycetes. It is a potent anti-cancer drug, which acts as a strong DNA-cutting agent, thereby causing cell death. BLMT has strong binding affinity to Bm and it protects against this lethal compound through drug sequestering. BLMT has two identically-folded subdomains, with the same alpha/beta fold; these two halves have no sequence similarity. BLMT is a dimer with two Bm-binding pockets formed at the dimer interface.