Effect of ribonuclease H from chick embryo on the covalent-linked poly(A)--poly(dA) complementary to poly(dT)...

In vitro poly(dA) synthesis on poly(dT) template can be initiated by poly(A) primer. Poly(A) chains are covalently extended by DNA polymerase. The reaction product consists of poly(dA) chain with poly(A) at their 5'-ends, hydrogen bonded to the template poly(dT). The primer poly(A) is linked to the product poly(dA) via a 3':5'-phosphodiester bond, and can be specifically removed by ribonuclease H from chick embryos, leaving a 5'-phosphate end of poly(dA). Poly- or oligoriboadenylate longer than the (pA)5 could serve as a priming activity to synthesize poly(A) covalently linked to poly(dA).