Purification and characterization of a deoxyriboendonuclease from Mycobacterium smegmatis.
A deoxyriboendonuclease has been purified to near homogeneity from a fast growing mycobacterium species, M. smegmatis and characterized to some extent. The size of enzyme is about 43 kDa as determined by a denaturing gel analysis. It shows optimum activity at 32 degrees C in Tris-HCl buffer (pH 7.2) containing 2.5 mM of MgCl2. Both EDTA and K+ but not Na+ inhibit its activity. Evidences show that the enzyme is not a restriction endonuclease but catalyzes the endonucleolytic cleavage of both the double- as well as the single-strand DNA non-specifically. It has been shown that the cleavage by this enzyme generates DNA fragments carrying phosphate groups at 5' ends and hydroxyl group at the 3' ends, respectively. Analysis reveals that no endonuclease having size and property identical to our deoxyriboendonuclease had been purified from M. smegmatis before. The property of our enzymes closely matches with the deoxyriboendonucleases purified from diverse sources including bacteria.
Mandal
Prajna
P
Department of Biochemistry, Bose Institute, Acaharya J. C. Bose Birth centenary Building, P-1/12, CIT Scheme VII M, Calcutta 700054, India.
Chakraborty
Phulghuri
P
Sau
Subrata
S
Mandal
Nitai Chandra
NC
D004247:DNA / Q000737:chemistry; D003851:Deoxyribonucleases / Q000737:chemistry* / Q000302:isolation & purification*; D004789:Enzyme Activation / Q000502:physiology; D004926:Escherichia coli / Q000201:enzymology; D008970:Molecular Weight; D020102:Mycobacterium smegmatis / Q000201:enzymology*; D009841:Oligonucleotides / Q000737:chemistry
D009841:Oligonucleotides; D004247:DNA; D003851:Deoxyribonucleases