Two DNA glycosylases in Esherichia coli which release primarily 3-methyladenine

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Biochemistry; (United States)

OSTI ID:5889500

Thomas, L; Yang, C; Goldthwait, D A

Two enzymes have been partially purified from Escherichia coli and designated 3-methyladenine DNA glycosylases I and II. The apparent molecular weight of glycosylase I is 20,000, and that of II is 27,000. Glycosylase I releases 3-methyladenine (3-MeA) while II releases 3-MeA, 3-methylguanine (3-MeG), 7-methylguanine (7-MeG), and 7-methyladenine (7-MeA). The rate of release of 3-MeA by glycosylase II is 30 times that of 7-MeG. Glycosylase I is missing in mutants tag 1 and tag 2. In crude extracts, the 3-MeA activity of II is approximately 10% of the total 3-MeA activity. A 50% inactivation at 48/sup 0/C required 5 min for I and 65 min for II. The 3-MeA and 7-MeG activities of the glycosylase II preparation could not be separated by isoelectric focusing, by chromatography of DEAE, Sephadex G-100, phosphocellulose, DNA-cellulose, or carboxymethylcellulose, or by heating at 50/sup 0/C.

• Research Organization: Case Western Reserve Univ. School of Medicine, Cleveland, OH
• OSTI ID: 5889500
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 21; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
ADENINES
AMINES
ANTIMETABOLITES
AROMATICS
AZAARENES
BACTERIA
BIOCHEMISTRY
CHEMICAL PROPERTIES
CHEMISTRY
CHROMATOGRAPHY
DNA
DRUGS
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
EXTRACTION CHROMATOGRAPHY
GLYCOSYL HYDROLASES
HETEROCYCLIC COMPOUNDS
HYDROLASES
LABELLED COMPOUNDS
MICROORGANISMS
MOLECULAR WEIGHT
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PURINES
SEPARATION PROCESSES
TRITIUM COMPOUNDS