Biomaterial Database

[Eremothecium ashbyii mutants resistant to 8-azaguanine. III. Nucleotide pyrophosphorylase activity of mutants with a varying degree of 8-azaguanine resistance]. 1982

S M Rozenfel'd, and V A Mironov, and V G Zhdanov

Eremothecium ashbyii mutants resistant to low and high concentrations of 8-azaguanine (AZG), have been obtained. In low resistant mutants (10(-4) M AZG) isolated by one step selection, the activity of GMP- and AMP-pyrophosphorylases was decreased, as compared with the initial sensitive strain. The stepwise increase of the mutants resistance to AZG resulted in increasing of resistance to 8-azaadenine and decreasing of the activity of GMP-pyrophosphorylase, while this did not affect the level of AMP-pyrophosphorylase. Characteristics of the cross-resistance of mutant to purine analogues and the level of nucleotide-pyrophosphorylases activity were discussed in the light of their possible influence on riboflavin biosynthesis.

UI	MeSH Term	Description	Entries
D007041	Hypoxanthine Phosphoribosyltransferase	An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or MERCAPTOPURINE to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.	Guanine Phosphoribosyltransferase,HPRT,Hypoxanthine-Guanine Phosphoribosyltransferase,IMP Pyrophosphorylase,HGPRT,HPRTase,Hypoxanthine Guanine Phosphoribosyltransferase,Phosphoribosyltransferase, Guanine,Phosphoribosyltransferase, Hypoxanthine,Phosphoribosyltransferase, Hypoxanthine-Guanine,Pyrophosphorylase, IMP
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010430	Pentosyltransferases	Enzymes of the transferase class that catalyze the transfer of a pentose group from one compound to another.
D004352	Drug Resistance, Microbial	The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).	Antibiotic Resistance,Antibiotic Resistance, Microbial,Antimicrobial Resistance, Drug,Antimicrobial Drug Resistance,Antimicrobial Drug Resistances,Antimicrobial Resistances, Drug,Drug Antimicrobial Resistance,Drug Antimicrobial Resistances,Drug Resistances, Microbial,Resistance, Antibiotic,Resistance, Drug Antimicrobial,Resistances, Drug Antimicrobial
D004718	Saccharomycetales	An order of fungi in the phylum Ascomycota that multiply by budding. They include the telomorphic ascomycetous yeasts which are found in a very wide range of habitats.	Budding Yeast,Endomycetales,Endomycopsis,Yeast, Budding,Budding Yeasts,Endomycetale,Endomycopses,Saccharomycetale,Yeasts, Budding
D000228	Adenine Phosphoribosyltransferase	An enzyme catalyzing the formation of AMP from adenine and phosphoribosylpyrophosphate. It can act as a salvage enzyme for recycling of adenine into nucleic acids. EC 2.4.2.7.	AMP Pyrophosphorylase,Transphosphoribosidase,APRTase,Phosphoribosyltransferase, Adenine,Pyrophosphorylase, AMP
D001203	Ascomycota	A phylum of fungi which have cross-walls or septa in the mycelium. The perfect state is characterized by the formation of a saclike cell (ascus) containing ascospores. Most pathogenic fungi with a known perfect state belong to this phylum.	Ascomycetes,Cochliobolus,Sclerotinia,Ascomycete,Ascomycotas,Sclerotinias
D001375	Azaguanine	One of the early purine analogs showing antineoplastic activity. It functions as an antimetabolite and is easily incorporated into ribonucleic acids.	Guanazolo,8-Azaguanine,8 Azaguanine