PMID- 1447218
OWN - NLM
STAT- MEDLINE
DCOM- 19921230
LR  - 20210823
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 267
IP  - 34
DP  - 1992 Dec 5
TI  - Stereoselective interaction with chiral phosphorothioates at the central DNA kink 
      of the EcoRI endonuclease-GAATTC complex.
PG  - 24810-8
AB  - We have probed the contacts between EcoRI endonuclease and the central phosphate 
      of its recognition site GAApTTC, using synthetic oligonucleotides containing 
      single stereospecific Rp- or Sp-phosphorothioates (Ps). These substitutions 
      produce subtle stereospecific effects on EcoRI endonuclease binding and cleavage. 
      An Sp-Ps substitution in one strand of the DNA duplex improves binding free 
      energy by -1.5 kcal/mol, whereas the Rp-Ps substitution has an unfavorable effect 
      (+0.3 kcal/mol) on binding free energy. These effects derive principally from 
      changes in the first order rate constants for dissociation of the enzyme-DNA 
      complexes. The first order rate constants for strand scission are also affected, 
      in that a strand containing Sp-Ps substitution is cleaved 2 to 3 times more 
      rapidly than a strand containing a normal prochiral phosphate, whereas a strand 
      containing Rp-Ps substitution is cleaved about 3 times slower than normal. As a 
      result, single-strand substitutions produce pronounced asymmetry in the rates of 
      cleavage of the two DNA strands, and this effect is exaggerated in an 
      Rp,Sp-heteroduplex. Ethylation-interference footprinting indicates that none of 
      the Ps substitutions cause any major change in contacts between endonuclease and 
      DNA phosphates. When an Sp-Ps localizes P = O in the DNA major groove, a 
      hydrogen-bonding interaction with the backbone amide-NH of Gly116 of the 
      endonuclease is improved relative to that with a prochiral phosphate having 
      intermediate P-O bond order and delocalized charge.
FAU - Lesser, D R
AU  - Lesser DR
AD  - Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
FAU - Grajkowski, A
AU  - Grajkowski A
FAU - Kurpiewski, M R
AU  - Kurpiewski MR
FAU - Koziolkiewicz, M
AU  - Koziolkiewicz M
FAU - Stec, W J
AU  - Stec WJ
FAU - Jen-Jacobson, L
AU  - Jen-Jacobson L
LA  - eng
GR  - R01 GM029207/GM/NIGMS NIH HHS/United States
GR  - GM-29207/GM/NIGMS NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Oligodeoxyribonucleotides)
RN  - 0 (Organothiophosphates)
RN  - 9007-49-2 (DNA)
RN  - EC 3.1.21.- (Deoxyribonuclease EcoRI)
SB  - IM
MH  - Base Sequence
MH  - Binding Sites
MH  - DNA/chemistry/*metabolism
MH  - Deoxyribonuclease EcoRI/chemistry/*metabolism
MH  - Kinetics
MH  - Models, Molecular
MH  - Molecular Sequence Data
MH  - Nucleic Acid Conformation
MH  - Oligodeoxyribonucleotides/chemical synthesis/chemistry/*metabolism
MH  - Organothiophosphates/*metabolism
MH  - Protein Conformation
MH  - Stereoisomerism
MH  - Structure-Activity Relationship
MH  - Substrate Specificity
MH  - Thermodynamics
EDAT- 1992/12/05 00:00
MHDA- 1992/12/05 00:01
CRDT- 1992/12/05 00:00
PHST- 1992/12/05 00:00 [pubmed]
PHST- 1992/12/05 00:01 [medline]
PHST- 1992/12/05 00:00 [entrez]
AID - S0021-9258(18)35836-8 [pii]
PST - ppublish
SO  - J Biol Chem. 1992 Dec 5;267(34):24810-8.