| 摘要 |
<p>A plasmid which, when introduced into a suitable host cell and grown under appropriate conditions, effects expression of a gene on the plasmid and production of a polypeptide having reverse transcriptase activity. The plasmid is a double-stranded DNA molecule which includes in a 5' to 3' order the following: a DNA sequence which includes an inducible promoter; a DNA sequence which includes an ATG initiation codon; the central portion of the Moloney murine leukemia virus (MuLV) pol gene, said central portion including a DNA sequence which encodes the polypeptide having reverse transcriptase activity; a DNA sequence which contains a gene associated with a selectable or identifiable phenotypic trait which is manifested when the vector is present in the host cell; and DNA sequence which contains an origin of replication from a bacterial plasmid capable of autonomous replication in the host cell. The invention also concerns a method for recovering purified enzymatically-active polypeptide having reverse transcriptase activity, the polypeptide being encoded by the plasmid pB6 B15.23, from a suitable host cell e.g. E. coli HB101 producing the polypeptide. Finally, the invention concerns use of the polypeptide to prepare complementary DNA (cDNA).</p> |
