[Properties of aminoglycoside-3'-phosphotransferases determined by kanamycin transposones Tn 601 and Tn 5].
Aminoglycoside-3'-phosphotransferase I and II (APT-3'-I and APT-3'-II) has been purified to homogenity from the cells of E. coli containing the plasmids R6 and JR67, respectively. The purification procedure involved competitive affinity chromatography on neomycin-sepharose and gel-filtration on Sephadex G-100. The specific activity of APT-3'-I with the substrates--lividomycin A, neomycin B, paromycin, ribostamycin, kanamycins A and B--are 4.3, 2.8, 2.1, 1.6, 0.9 and 0.8 mol/min. mg protein, respectively. The specific activity of APT-3'-II with the substrates--ribostamycin, paromycin, kanamycins A and B, neomycin B--are 8.0, 7.2, 4.0, 4.5 and 3.6, respectively. Mg2+ is required for the activity of both enzymes. Co2+, Zn2+ and Mn2+ are active in case of APT-3'-I; however, these cations are less active than Mg2+. The pH-optimum of APT-3'-I and APT-3'-II is 7.0--7.5. High ionic strength is required for the activity of both enzymes. The molecular weights of APT-3'-I and APT-3'-II are about 36 000 and 26 000, respectively. The amino acid composition of APT-3'-I and APT-3'-II was determined. Both enzymes contain tryptophane residues whose fluorescence intensity decreased when ATP, but not amino-glycoside antibiotics, is added. The interrelationship between the molecular weights of these enzymes and the sizes of the loops of transposones Tn 601 and Tn 5, encoding APT-3'-I and APT-3'-II, is discussed.
D000596:Amino Acids / Q000032:analysis; D002413:Cations, Divalent; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology*; D005779:Immunodiffusion; D007612:Kanamycin; D019868:Kanamycin Kinase; D007700:Kinetics; D008970:Molecular Weight; D010770:Phosphotransferases / Q000302:isolation & purification / Q000378:metabolism*; D010957:Plasmids; D013379:Substrate Specificity
D000596:Amino Acids; D002413:Cations, Divalent; D007612:Kanamycin; D010770:Phosphotransferases; D019868:Kanamycin Kinase
Svoistva aminoglikozid-6'-fosfotransferaz, determiniruemykh Kapamitsinovymi transpozonami Tn 601 i Tn 5.