48 



MAURICE J. BESSMAN 



TABLE XXII 

 Replacement of Natural Bases by Analogs in Enzymatic Synthesis of DNA" 



" From Bessman et al. (1958b). 



'' Control values are m/xmoles of radioactive deoxynucleotide incorporated into 

 DNA in the absence of analog. Incubation mixtures contained in 0.3 ml, 5 m^imoles 

 each of TTP, dATP, dCTP, and dGTP; 2 Mmoles of MgClj; 20 Mmoles of potassium 

 phosphate (pH 7.4); 10 Mg of calf-thymus DNA; and 1 /ug of enzyme fraction VII-R. 

 Experiments were performed at 37°C for 30 minutes. Labeled substrates were: dCP'^'PP 

 in E.xpts. 1, 2, and 5a; TP^^PP in Expts. la, 3, 4, and 5; and dOP^^PP in E.xpts. 2a, 3a, 

 and 4a. 



" The percentage value represents the fraction of the labeled substrate incorporated 

 when the analog (5 mMmoles) was used instead of a natural base. All bases, natural or 

 analog, were supplied as the deoxjnucleoside triphosphates. Values of 5% or below are 

 near the limit of detect ability and are of questionable significance. 



TABLE XXIII 



I.\CURPUR.\TION OF P'^-DeOXYURIDYLATE INTO DNA" 



Substrates'* 



P^^-deo.xynucleotide 



incorporated 



(m^moles) 



U + T + C + A+Ci 

 Omit T 

 Omit C 

 Omit A 

 OmitG 



U+T+C+A+G 

 Omit U 



14 

 . 38 

 0.01 

 0.01 

 0.01 



0.37 

 0.77 



« From Bessman et al. (1958b). 



* U = dUTP; U = dUP^^pp. '1^ = '["pi>. ^l = TP32PP; C = dCTP; A = dATP; 

 G = dGTP. 



