While all NTPs can bind the entry site, only an NTP matched for base-pairing with the DNA template binds the addition site for attachment to the growing RNA strand, Kornberg said.

• 尽管所有的NTP都可结合到插入位点，但是只有与DNA模板相匹配的NTP才能够与添加位点结合，连接到正在延长的RNA链上。