Reasons and limits of substrate activity of modified L-dNTP in DNA biosynthesis

Theoretical and experimental analysis of interaction of modified D- and L- dNTP as substrates for template-dependent and template-independent DNA poly merases was performed. It is shown that if the modified nucleoside 5'-triph osphates do not contain a substituent in position 3' DNA chains can be exte nded by both strereoisomeric series with the same kinetic parameters. But t he presence of even a 3'- hydroxy group in L-dNTP prevents their incorporat ion into the DNA chain.