Fidelity of fractionated deoxyribonucleic acid polymerases from human placenta

Journal Article · Tue Jan 08 00:00:00 EST 1980 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00542a033· OSTI ID:5483803

Krauss, S W; Linn, S

Deoxyribonucleic acid (DNA) polymerase activities from human placenta have been fractionated and classified amoung the ..cap alpha.., ..beta.., and ..gamma.. types by using the criteria of size, ability to utilize various synthetic template-primers, and sensitivity to phosphate, N-ethylmaleimide, aphidicolin, and 2', 3'-dideoxythymidine 5'-triphosphate. Reverse transcriptase and delta-polymerase activities were not detected. ..cap alpha.. activity resolved into two fractions on diethylaminothylcellulose which could be distinguished catalytically by their template-primer preferences. Similarly, multiple species of ..beta..-polymerase were obtained upon purification by phosphocellulose or glycerol gradient sedimentation. Each DNA polymerase fraction was tested for misincorporation frequencies with synthetic template-primers and either Mn/sup 2 +/ or Mg/sup 2 +/. All ..cap alpha..-polymerases copied the templates with relatively high fidelity, though absolute values dependended upon the length of primer and the primer/template ratio. With Mn/sup 2 +/ present, an 8.6S species of ..beta..-polymerase copied the synthetic templates very accurately, but 6.3S and 4.6S forms copied the same polymers relatively unfaithfully. The 8.6S form could be converted to a 4.8S species with a concomitant loss of fidelity. ..gamma..-Polymerase also copied deoxyribopolymers relatively inaccurately in the presence of Mn/sup 2 +/. The relative concentrations of complementary to noncomplementary triphosphates affected the frequency of misincorporation for ..beta.. and ..gamma.. activities. Conversely, ..cap alpha..-polymerase did not show similar behavior at saturating triphosphate concentrations. None of the placental polymerase fractions contained exonuclease activity that could discriminate between complementary and noncomplementary 3' ends.

• Research Organization: Univ. of California, Berkeley
• DOE Contract Number: EY-765-03-0034
• OSTI ID: 5483803
• Journal Information: Biochemistry; (United States), Vol. 19:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DNA
BIOSYNTHESIS
DNA REPLICATION
BIOLOGICAL PATHWAYS
POLYMERASES
ENZYME ACTIVITY
FRACTIONATION
CHROMATOGRAPHY
EXPERIMENTAL DATA
MAN
PLACENTA
POLYMERS
TABLES
ANIMALS
DATA
DATA FORMS
ENZYMES
FETAL MEMBRANES
INFORMATION
MAMMALS
MEMBRANES
NUCLEIC ACID REPLICATION
NUCLEIC ACIDS
NUMERICAL DATA
ORGANIC COMPOUNDS
PRIMATES
SEPARATION PROCESSES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques