Kinetics of incorporation of O/sup 6/-methyldeoxyguanosine monophosphate during in vitro DNA synthesis

Journal Article · Tue Sep 11 04:00:00 EDT 1984 · Biochemistry; (United States)

OSTI ID:5416402

Snow, E T; Foote, R S; Mitra, S

O/sup 6/-Methyldeoxyguanosine triphosphate (m/sup 6/dGTP), known to be produced in vivo by methylation of deoxyguanosine triphosphate with simple methylating mutagens, is utilized by prokaryotic DNA polymerases during in vitro replication of synthetic and natural DNA template-primers. A study of the kinetic behavior of m/sup 6/dGTP during DNA replication in vitro and of its effect on DNA replication indicates that m/sup 6/dGTP acts as an analogue of dATP with K/sub m//sup app/ of about 6 ..mu..M for Escherichia coli DNA polymerase I (Klenow fragment) compared to the K/sub m//sup app/ of about 0.8 ..mu..M for dATP. m/sup 6/dGTP is not incorporated in the complete absence of dATP (a competitive inhibitor). m/sup 6/dGTP also inhibits in vitro DNA synthesis. Different DNA polymerases behave differently in utilization and turnover of m/sup 6/dGTP. T4 DNA polymerase shows stronger discrimination against m/sup 6/dGMP incorporation than either T5 DNA polymerase or E. coli DNA polymerase I. The possibility that m/sup 6/dGTP is unlikely to contribute significantly to in vivo mutation is discussed.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5416402
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 23:19; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AROMATICS
ATP
AZAARENES
BACTERIA
BIOCHEMICAL REACTION KINETICS
DATA
DNA POLYMERASES
DNA REPLICATION
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
EXPERIMENTAL DATA
GUANOSINE
HETEROCYCLIC COMPOUNDS
IN VITRO
INFORMATION
KINETICS
MICROORGANISMS
MUTAGENS
NUCLEIC ACID REPLICATION
NUCLEOSIDES
NUCLEOTIDES
NUCLEOTIDYLTRANSFERASES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PURINES
REACTION KINETICS
RIBOSIDES
TRANSFERASES