Targeting of DNA polymerase to the adenovirus origin of DNA replication by interaction with nuclear factor I.
Efficient initiation by the DNA polymerase of adenovirus type 2 requires nuclear factor I (NFI), a cellular sequence-specific transcription factor. Three functions of NFI--dimerization, DNA binding, and activation of DNA replication--are colocalized within the N-terminal portion of the protein. To define more precisely the role of NFI in viral DNA replication, a series of site-directed mutations within the N-terminal domain have been generated, thus allowing the separation of all three functions contained within this region. Impairment of the dimerization function prevents sequence-specific DNA binding and in turn abolishes the NFI-mediated activation of DNA replication. NFI DNA-binding activity, although necessary, is not sufficient to activate the initiation of adenovirus replication. A distinct class of NFI mutations that abolish the recruitment of the viral DNA polymerase to the origin also prevent the activation of replication. Thus, a direct interaction of NFI with the viral DNA polymerase complex is required to form a stable and active preinitiation complex on the origin and is responsible for the activation of replication by NFI.
Armentero
M T
MT
Institut de Biologie Animale, Université de Lausanne, Switzerland.
Horwitz
M
M
Mermod
N
N
D000260:Adenoviruses, Human / Q000235:genetics*; D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D051839:NFI Transcription Factors; D011485:Protein Binding; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*; D014779:Virus Replication
D017931:DNA Primers; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D014157:Transcription Factors; D014764:Viral Proteins; C056461:terminal protein, adenovirus; C080333:transcription factor nuclear factor 1; D004259:DNA-Directed DNA Polymerase