Document 0290
 DOCN  M95A0290
 TI    Recognition by viral and cellular DNA polymerases of nucleosides bearing
       bases with nonstandard hydrogen bonding patterns.
 DT    9510
 AU    Horlacher J; Hottiger M; Podust VN; Hubscher U; Benner SA;
       Bio-Organische Chemie, Eidgenossiche Technische Hochschule; Zurich,
       Switzerland.
 SO    Proc Natl Acad Sci U S A. 1995 Jul 3;92(14):6329-33. Unique Identifier :
       AIDSLINE MED/95327640
 AB    The ability of DNA polymerases (pols) to catalyze the template-directed
       synthesis of duplex oligonucleotides containing a nonstandard
       Watson-Crick base pair between a nucleotide bearing a
       5-(2,4-diaminopyrimidine) heterocycle (d kappa) and a nucleotide bearing
       either deoxyxanthosine (dX) or N1-methyloxoformycin B (pi) has been
       investigated. The kappa-X and kappa-pi base pairs are jointed by a
       hydrogen bonding pattern different from and exclusive of those joining
       the AT and GC base pairs. Reverse transcriptase from human
       immunodeficiency virus type 1 (HIV-1) incorporates dXTP into an
       oligonucleotide opposite d kappa in a template with good fidelity. With
       lower efficiency and fidelity, HIV-1 reverse transcriptase also
       incorporates d kappa TP opposite dX in the template. With d pi in the
       template, no incorporation of d kappa TP was observed with HIV reverse
       transcriptase. The Klenow fragment of DNA pol I from Escherichia coli
       does not incorporate d kappa TP opposite dX in a template but does
       incorporate dXTP opposite d kappa. Bovine DNA pols alpha, beta, and
       epsilon accept neither dXTP opposite d kappa nor d kappa TP opposite d
       pi. DNA pols alpha and epsilon (but not beta) incorporate d kappa TP
       opposite dX in a template but discontinue elongation after incorporating
       a single additional base. These results are discussed in light of the
       crystal structure for pol beta and general considerations of how
       polymerases must interact with an incoming base pair to faithfully copy
       genetic information.
 DE    Base Composition  Base Sequence  Comparative Study
       *Deoxyribonucleosides  DNA Polymerase I/METABOLISM  DNA Polymerase
       II/METABOLISM  DNA Polymerases/*METABOLISM  Escherichia coli/ENZYMOLOGY
       *Formycins  Hydrogen Bonding  HIV-1/ENZYMOLOGY  Molecular Sequence Data
       Oligodeoxyribonucleotides/*CHEMISTRY/*METABOLISM  *Pyrimidine
       Nucleosides  Recombinant Proteins/METABOLISM  Reverse
       Transcriptase/*METABOLISM  Structure-Activity Relationship  Support,
       Non-U.S. Gov't  Templates  Thymus Gland/ENZYMOLOGY  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).