Molecular Forms of Deoxyribonucleic Acid present in the Purified Enzyme from Mycobacterium smegmatis

1979 ◽  
Vol 7 (1) ◽  
pp. 26-28 ◽  
Author(s):  
FRANK G. WINDER ◽  
PATRICIA CARTY
Keyword(s):  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
Molecular Forms

scholarly journals A nucleoside triphosphate-dependent deoxyribonucleic acid-breakdown system in Mycobacterium smegmatis, and the effect of iron limitation on the activity of this system

1969 ◽  
Vol 111 (5) ◽  
pp. 679-687 ◽  
Author(s):  
F. G. Winder ◽  
M. P. Coughlan
Keyword(s):  
Dna Content ◽  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
Maximal Activity ◽  
Enzyme Concentration ◽  
Iron Limitation ◽  
Nucleoside Triphosphate ◽  
Primary Products ◽  
Rate Of Reaction ◽  
Optimum Ph

1. The presence of a nucleoside triphosphate-dependent DNA-breakdown system was demonstrated in extracts of Mycobacterium smegmatis. Its activity was increased substantially by iron limitation, apparently after the fall in DNA content that took place under these conditions. A maximal activity of about 0·2μmole of deoxyribonucleotide/30min./mg. of protein was found in crude extracts. 2. After slight purification by streptomycin treatment, the enzyme showed maximal activity with undenatured DNA (Km≃200μg./ml.), ATP (Km≃1·2mm) or UTP, CTP and GTP giving lower activity and pyrophosphate giving none, and Mg2+ ions (optimum concn. 12mm). The optimum pH was 8·5. 3. In the assay system there was proportionality between enzyme concentration and rate of reaction, but the rate fell off with time. 4. ATP was broken down in the reaction and monodeoxy-ribonucleotides were among the products, but the presence of some oligodeoxy-ribonucleotides was not excluded and the degree of phosphorylation of the primary products was uncertain.

scholarly journals Partial purification of deoxyribonucleic acid polymerase from Mycobacterium smegmatis

1968 ◽  
Vol 110 (2) ◽  
pp. 10P
Author(s):  
F G A Winder ◽  
M S McNulty ◽  
L A Callender
Keyword(s):  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
Partial Purification

Isolation and characterization of nocardia-like variants of Mycobacterium smegmatis

1976 ◽  
Vol 22 (10) ◽  
pp. 1480-1491 ◽  
Author(s):  
R. J. Hawley ◽  
T. Imaeda ◽  
Nora Mann
Keyword(s):  
Fatty Acids ◽  
Mitomycin C ◽  
Ultraviolet Light ◽  
Mycobacterium Smegmatis ◽  
Deoxyribonucleic Acid ◽  
New Class ◽  
Parental Type ◽  
Isolation And Characterization ◽  
Hydroxylated Fatty Acids

Orange-red-pigmented (OR) colonies were isolated from cream-yellow-pigmented Mycobacterium smegmatis after exposure to either mycobacteriophage MC4 or ultraviolet light; these variant strains were designated OR4 and ORuv, respectively. Early subculture of OR-colonies did not show any segregation of parental-type cells. However, colonies resembling the parental strains, possibly representing a back mutant (REV-OR4), were occasionally found during subculture of established OR-colonies or upon treatment with N-nitroso-N′-nitro-N-methylguanidine. The OR-variants were characterized by their lytic response to nocardiophage, but not to mycobacteriophages, presence of α-branched, β-hydroxylated fatty acids of the Nocardia-type, and a guanine plus cytosine value of deoxyribonucleic acid (DNA) between 62 and 64 mol %. They were more resistant to the lethal action of both ultraviolet light and mitomycin C treatment than the parental and back mutant strains.Although the OR-variants in this study possess characteristics common to the genus Nocardia or some of the 'rhodochrous' mycobacteria, evidence is presented that they form a new class of mycobacterial variants.

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