DNA duplexes containing the natural methylated bases N6-methyladenine (m6Ade), N4-methylcytosine (m4Cyt) or C5-methylcytosine (m5Cyt) in one strand of the recognition sequence are resistant to EcoRII restriction endonuclease (R.EcoRII). Hydrolysis of these modified duplexes was observed in the presence of the canonical substrate. Incorporation of m4Cyt or m5Cyt into both strands of the recognition sequence precludes such activation by a canonical substrate. R.EcoRII also fails to cleave substrate analogs in which one of the nucleosides in the recognition site is replaced by the 1,2-dideoxyribose (D) or by 1,3-propanediol (Prd) (modeling DNA with an abasic site). The hydrolysis of DNA duplexes with non-nucleotide inserts is also activated in the presence of canonical substrate. Thus, the two-substrate mechanism of EcoRII-DNA interaction allows hydrolysis of apurinic/apyrimidinic and hemimethylated DNA.
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http://dx.doi.org/10.1016/0378-1119(94)00737-d | DOI Listing |
J Phys Chem B
January 2025
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
University of Wisconsin Madison, Chemistry, 1101 University Ave, 53706, Madison, UNITED STATES OF AMERICA.
Many applications of enzymes benefit from activity on structurally diverse substrates. Here, we sought to engineer the decarboxylative aldolase UstD to perform a challenging C-C bond forming reaction with ketone electrophiles. The parent enzyme had only low levels of activity, portending multiple rounds of directed evolution and a possibility that mutations may inadvertently increase the specificity of the enzyme for a single model screening substrate.
View Article and Find Full Text PDFCyclin F, a non-canonical member of the cyclin protein family, plays a critical role in regulating the precise transitions of cell-cycle events. Unlike canonical cyclins, which bind and activate cyclin-dependent kinases (CDKs), Cyclin F functions as a substrate receptor protein within the Skp1-Cullin-F box (SCF) E3 ubiquitin ligase complex, enabling the ubiquitylation of target proteins. The structural features that distinguish Cyclin F as a ligase adaptor and the mechanisms underlying its selective substrate recruitment over Cyclin A, which functions in complex with CDK2 at a similar time in the cell cycle, remain largely unexplored.
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View Article and Find Full Text PDFTrends Pharmacol Sci
January 2025
Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy. Electronic address:
Current therapies for diabetes and atherosclerotic cardiovascular diseases (ACVDs) mainly target metabolic risk factors, but often fall short in addressing systemic inflammation, a key driver of disease onset and progression. Advances in our understanding of the biology of neutrophils, the cells that are principally involved in inflammatory situations, have highlighted their pivotal role in cardiometabolic diseases. Yet, neutrophils can reprogram their immune-metabolic functions based on the energetic substrates available, thus influencing both tissue homeostasis and the resolution of inflammation.
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