<p>By competing with the natural substrate deoxyguanosine triphosphate, entecavir functionally inhibits all three activities of the HBV polymerase (reverse transcriptase, rt):</p>

<ul>
	<li>Base priming,</li>
	<li>Reverse transcription of the negative strand from the pregenomic messenger RNA, and</li>
	<li>Synthesis of the positive strand of HBV DNA. Upon activation by kinases, the drug can be incorporated into the DNA which has the ultimate effect of inhibiting the HBV polymerase activity.</li>
</ul>