摘要 |
Reverse transcription of retroviruses is initiated from an 18 nucleotide primer binding site (PBS), located within the 5' region of viral genomic RNA, to which the host cell-derived tRNA primer is annealed and also involves viral genomic sequences outside the PBS. Significantly lower levels of viral DNA are detected in cells infected with proviral DNA clones of human immunodeficiency virus (HIV) selectively deleted in regard to a segment found immediately downstream of the PBS. This segment is involved in efficient expression of each of viral DNA, mRNA, and infectious virus. The deleted DNA clones are useful for the preparation of an HIV vaccine. |