scholarly journals The oxidative DNA glycosylases of Mycobacterium tuberculosis exhibit different substrate preferences from their Escherichia coli counterparts

DNA Repair ◽  
2010 ◽  
Vol 9 (2) ◽  
pp. 177-190 ◽  
Author(s):  
Yin Guo ◽  
Viswanath Bandaru ◽  
Pawel Jaruga ◽  
Xiaobei Zhao ◽  
Cynthia J. Burrows ◽  
...  
Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 110
Author(s):  
Anna K. Riebisch ◽  
Sabrina Mühlen ◽  
Yan Yan Beer ◽  
Ingo Schmitz

Autophagy is a highly conserved and fundamental cellular process to maintain cellular homeostasis through recycling of defective organelles or proteins. In a response to intracellular pathogens, autophagy further acts as an innate immune response mechanism to eliminate pathogens. This review will discuss recent findings on autophagy as a reaction to intracellular pathogens, such as Salmonella typhimurium, Listeria monocytogenes, Mycobacterium tuberculosis, Staphylococcus aureus, and pathogenic Escherichia coli. Interestingly, while some of these bacteria have developed methods to use autophagy for their own benefit within the cell, others have developed fascinating mechanisms to evade recognition, to subvert the autophagic pathway, or to escape from autophagy.


2003 ◽  
Vol 185 (20) ◽  
pp. 6005-6015 ◽  
Author(s):  
Krishna K. Gopaul ◽  
Patricia C. Brooks ◽  
Jean-François Prost ◽  
Elaine O. Davis

ABSTRACT The recA gene of Mycobacterium tuberculosis is unusual in that it is expressed from two promoters, one of which, P1, is DNA damage inducible independently of LexA and RecA, while the other, P2, is regulated by LexA in the classical way (E. O. Davis, B. Springer, K. K. Gopaul, K. G. Papavinasasundaram, P. Sander, and E. C. Böttger, Mol. Microbiol. 46:791-800, 2002). In this study we characterized these two promoters in more detail. Firstly, we localized the promoter elements for each of the promoters, and in so doing we identified a mutation in each promoter which eliminates promoter activity. Interestingly, a motif with similarity to Escherichia coli σ70 −35 elements but located much closer to the −10 element is important for optimal expression of P1, whereas the sequence at the −35 location is not. Secondly, we found that the sequences flanking the promoters can have a profound effect on the expression level directed by each of the promoters. Finally, we examined the contribution of each of the promoters to recA expression and compared their kinetics of induction following DNA damage.


2005 ◽  
Vol 10 (7) ◽  
pp. 725-729 ◽  
Author(s):  
Upasana Singh ◽  
Vinita Panchanadikar ◽  
Dhiman Sarkar

Mycobacterium tuberculosis glutamine synthetase (GS) is an essential enzyme involved in the pathogenicity of the organism. The screening of a compound library using a robust high-throughput screening (HTS) assay is currently thought to be the most efficient way of getting lead molecules, which are potent inhibitors for this enzyme. The authors have purified the enzyme to a >90% level from the recombinant Escherichia coli strain YMC21E, and it was used for partial characterization as well as standardization experiments. The results indicated that the Kmof the enzyme for L-glutamine and hydroxylamine were 60 mM and 8.3 mM, respectively. The Km for ADP, arsenate, and Mn2+ were 2 [.proportional]M, 5 [.proportional]M, and 25 [.proportional]M, respectively. When the components were adjusted according to their Km values, the activity remained constant for at least 3 h at both 25° C and 37° C. The Z′ factor determined in microplate format indicated robustness of the assay. When the signal/noise ratios were determined for different assay volumes, it was observed that the 200-[.proportional]l volume was found to be optimum. The DMSO tolerance of the enzyme was checked up to 10%, with minimal inhibition. The IC50 value determined for L-methionine S-sulfoximine on the enzyme activity was 3 mM. Approximately 18,000 small molecules could be screened per day using this protocol by a Beckman Coulter HTS setup.


Gene ◽  
1999 ◽  
Vol 240 (2) ◽  
pp. 361-370 ◽  
Author(s):  
Nicola J. Mulder ◽  
Ros E. Powles ◽  
Harold Zappe ◽  
Lafras M. Steyn

INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (06) ◽  
pp. 18-23
Author(s):  
U. V. Laddi ◽  
◽  
S. R. Desai

Some new 5-[(((α-phenyl/methyl)benzylidene)amino)oxy]methyl/ethyl-2-[4-(substituted aryl)/allyl)] amino-1,3,4-oxadiazoles (4a-p), 3-[(((α-phenyl/methyl)- benzylidene) amino)oxy]methyl/ethyl-4-(4- substitutedaryl)/allyl-5-mercapto-1,2,4-triazoles (5a-p) and 5-[(((α-phenyl/methyl)-benzylidene)amino) oxy]- methyl/ethyl-2-[4-(substituted aryl)/allyl)]amino-1,3,4-thiadiazoles (6a-p) were prepared starting from α/β-[((α-(phenyl/methyl)benzylidene)amino)oxy acetic/propionic acid hydrazides (1a-d). The structures of all the compounds have been established by elemental and spectral (IR, 1HNMR and mass) analysis. All the newly synthesised compounds have been screened for their antimicrobial activity against Escherichia coli, Bacillus cirroflagellosus, Aspergillus niger and Rhizoctonia bataticola. Some of the newly synthesised compounds have been evaluated for antituberculosis activity against Mycobacterium tuberculosis H37Rv strain by BACTEC radiometric system at Southern Research Institute, Birmingham, AL and Frederick Research Centre, Frederick, MD. Significant antimicrobial activity is observed against Escherichia coli and Rhizoctonia bataticola. A few compounds also exhibited interesting antitubercular activity against Mycobacterium tuberculosis H37Rv strain.


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