AAV PHP.S-Syn-Cre

AAV is a small (~25 nm in diameter), non-enveloped, single-stranded DNA (ssDNA) virus. They are classified as dependent viruses - a genus belonging to the family Parvoviridae. As the genus name implies, AAV replication and production of progenitor viral particles are dependent on co-infection with a helper virus, such as adenovirus, herpes virus, or vaccinia virus. In the absence of these helper viruses, latent infection of AAV occurs by integration into the host genome, preferentially at the AAVS1 locus on chromosomal location 19q13.

The 4.7 kb ssDNA genome of AAV is packaged in both (+) and (−) single-stranded orientations. It consists of inverted terminal repeats (ITRs), which are structural elements required for second-strand synthesis, genome amplification, integration into chromosomes, and ssDNA packaging. The ITRs flank four genes: rep, cap, aap, and the newly discovered maap. The rep gene encodes four nonstructural proteins (Rep40, Rep52, Rep68, Rep78) of different molecular weights. They are produced from two spliced ​​mRNAs whose expression is controlled by two promoters, p5 and p19. Rep proteins are important regulators of AAV integration, reactivation, replication, and genome packaging. The expression of the cap gene is controlled by the p40 promoter, which produces three structural proteins, VP1 (viral protein-1; 87 kDa), VP2 (72 kDa), and VP3 (62 kDa). These proteins are produced from two spliced ​​mRNAs in a ratio of 1:1:10 (VP1:VP2:VP3) and assemble an icosahedral capsid composed of 60 VPs.