Inactivation of blasticidin S by Bacillus cereus. V. Purification and characterization of blasticidin S-deaminase mediated by a plasmid from blasticidin S resistant Bacillus cereus K55-S1.
Blasticidin S (BS) deaminase (BSR) from a BS-resistant strain, Bacillus cereus K55-S1, was purified to homogeneity. Molecular weights determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by gel filtration on HPLC are about 15500 and 35000, respectively, indicating the enzyme is a homodimer. The amino acid composition and N-terminal sequence of BSR are the same as those deduced from the nucleotide sequence of the BS-resistant gene, bsr. The optimum temperature and pH for enzyme activity are 60-65 degrees C and near 10.0, respectively. The activity of BSR is inhibited by Cu2+, Hg2+, and p-chloromercuric benzoate (PCMB). Inhibition by PCMB or HgCl2 is reversible by the addition of SH reagents. The enzyme catalyzes the deamination of BS and its derivatives, but not cytosine nucleosides.
Nawa
K
K
Kyoritsu College of Pharmacy, Tokyo, Japan.
Tamura
Y
Y
Sato
K
K
Hattori
J
J
Shimotohno
K W
KW
Endo
T
T
D000619:Aminohydrolases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors*; D001409:Bacillus cereus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D002853:Chromatography, Liquid; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D009705:Nucleosides / Q000037:antagonists & inhibitors; D010957:Plasmids; D013379:Substrate Specificity; D013696:Temperature
D000900:Anti-Bacterial Agents; D009705:Nucleosides; C004500:blasticidin S; D000619:Aminohydrolases; C019795:blasticidin S deaminase