Influence of the RNase H domain of retroviral reverse transcriptases on the metal specificity and substrate selection of their polymerase domains

Table 2 Steady State Kinetic Parameters of the Wild Type and Chimeric Reverse Transcriptases

Template-primer	Enzyme	K_mdNTP μM	Mn²⁺ K_cat S^-1	K_cat/K_m S^-1 M^-1 × 10²	K_mdNTP μM	Mg²⁺ K_cat S^-1	K_cat/K_m S^-1 M^-1 × 10²
U5-PBS RNA/17-mer DNA	WT HIV-1 RT	5.8	0.009	15.5	1.7	0.005	29.4
	Chim HIV-1 RT	945.5	0.040	0.4	702.8	0.050	0.7
	WT MuLV RT	2.0	0.003	15.0	16.7	0.006	3.6
	Chim MuLV RT	197.6	0.040	2.0	157.0	0.030	1.9
	M-Pol	2.9	0.004	13.8	301.8	0.021	0.7
U5-PBS 49-mer DNA/17-mer DNA	WT HIV-1 RT	2.8	0.029	103.6	1.3	0.035	269.2
	Chim HIV-1 RT	204.8	0.024	1.2	691.0	0.048	0.69
	WT MuLV RT	1.6	0.013	81.3	10.6	0.015	14.2
	Chim MuLV RT	14.8	0.055	37.2	433.0	0.048	1.1
	M-Pol	1.4	0.012	85.7	181.5	0.017	0.94

The steady-state kinetic parameters for wild-type reverse transcriptase from HIV-1 and MuLV and their chimeric derivatives were measured on heteropolymeric RNA and DNA template-primer in the presence of Mg⁺² and Mn⁺² as the divalent cation. These determinations were carried out at subsaturating concentration of dNTP substrates.

ISSN: 1743-422X