DNA polymerase beta catalytic efficiency mirrors the Asn279-dCTP H-bonding strength.
Ternary complexes of wild type or mutant form of human DNA polymerase beta (pol beta) bound to DNA and dCTP substrates were studied by molecular dynamics (MD) simulations. The occurrences of contact configurations (CC) of structurally important atom pairs were sampled along the MD trajectories, and converted into free-energy differences, DeltaG(CC). DeltaG(CC) values were correlated with the experimental binding and catalytic free energies for the wild type pol beta and its Arg183Ala, Tyr271Ala, Asp276Val, Lys280Gly, Arg283Ala, and Glu295Ala mutants. The correlation coefficients show that the strength of the H-bond between dCTP and Asn279 is a strong predictor of the mutation-induced changes in the catalytic efficiency of pol beta. This finding is consistent with the view that enzyme preorganization plays a major role in controlling DNA polymerase specific activity.
Martínek
Václav
V
Department of Chemistry, Loyola University Chicago, Chicago, IL 60626, USA.
Bren
Urban
U
Goodman
Myron F
MF
Warshel
Arieh
A
Florián
Jan
J
D001216:Asparagine / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D019951:DNA Polymerase beta / Q000737:chemistry* / Q000378:metabolism*; D017931:DNA Primers / Q000378:metabolism; D003845:Deoxycytosine Nucleotides / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding; D055672:Static Electricity; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D017931:DNA Primers; D003845:Deoxycytosine Nucleotides; C024107:2'-deoxycytidine 5'-triphosphate; D001216:Asparagine; D019951:DNA Polymerase beta