Characterization of DNA restriction and modification activities inNeisseriaspecies

Characterization of Avian Pasteurella multocida Isolates by Protein Profiles and Restriction Enzyme Analysis of Chromosomal DNA

Substrate DNA and cofactor regulate the activities of a multi-functional restriction-modification enzyme, BcgI.

The BcgI restriction-modification system consists of two subunits, A and B. It is a bifunctional protein complex which can cleave or methylate DNA. The regulation of these competing activities is determined by the DNA substrates and cofactors. BcgI is an active endonuclease and a poor methyltransferase on unmodified DNA substrates. In contrast, BcgI is an active methyltransferase and an inactiv...

DNA restriction-modification systems mediate plasmid maintenance.

Two plasmid-carried restriction-modification (R-M) systems, EcoRI (from pMB1 of Escherichia coli) and Bsp6I (from pXH13 of Bacillus sp. strain RFL6), enhance plasmid segregational stability in E. coli and Bacillus subtilis, respectively. Inactivation of the endonuclease or the presence of the methylase in trans abolish the stabilizing activity of the R-M systems. We propose that R-M systems med...

synthesis and characterization of some macrocyclic schiff bases

ماکروسیکلهای شیف باز از اهمیت زیادی در شیمی آلی و دارویی برخوردار می باشند. این ماکروسیکلها با دارابودن گروه های مناسب در مکانهای مناسب می توانند فلزاتی مثل مس، نیکل و ... را در حفره های خود به دام انداخته، کمپلکسهای پایدار تولید نمایند. در این پایان نامه ابتدا یک دی آلدئید آروماتیک از گلیسیرین تهیه می شود و در مرحله بعدی واکنش با دی آمینهای آروماتیک و یا آلیفاتیک در رقتهای بسیار زیاد منجر به ت...

Three Chromosomally Located Systems of DNA Restriction and Modification

Since the role of DNA restriction-modification (R-M) systems of hsd genes has been elucidated, recipient cells for unmodified or foreign DNA are usually restrictionless mutants. Such mutants may either modify and have the phenotype rm+ or fail to modify and have the phenotype rm-. Each R-M system consists of three genes: hsdS for specificity, hsdR for restriction, and hsdM for modification (1)....