The Chilo iridescent virus DNA polymerase promoter contains an essential AAAAT motif.
The delayed-early DNA polymerase promoter of Chilo iridescent virus (CIV), officially known as Invertebrate iridescent virus, was fine mapped by constructing a series of increasing deletions and by introducing point mutations. The effects of these mutations were examined in a luciferase reporter gene system using Bombyx mori cells transfected with promoter constructs and infected with CIV. When the size of the upstream element was reduced from position -19 to -15, relative to the transcriptional start site, the luciferase activity was reduced to almost zero. Point mutations showed that each of the 5 nt (AAAAT) located between -19 and -15 were equally essential for promoter activity. Mutations at individual bases around the transcription initiation site showed that the promoter extended until position -2 upstream of the transcription start site. South-Western analysis showed that a protein of approximately 100 kDa interacted with the -19 nt promoter fragment in CIV-infected cells. This binding did not occur with a point mutant that lacked promoter activity. The AAAAT motif was also found in the DNA polymerase promoter region of other iridoviruses and in other putative CIV delayed-early genes.
Nalçacioğlu
Remziye
R
Department of Biology, Faculty of Arts and Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.|Laboratory of Virology, Wageningen University, Binnenhaven 11, Wageningen, 6709 PD, The Netherlands.
Ince
Ikbal Agah
IA
Department of Biology, Faculty of Arts and Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.|Laboratory of Virology, Wageningen University, Binnenhaven 11, Wageningen, 6709 PD, The Netherlands.
Vlak
Just M
JM
Laboratory of Virology, Wageningen University, Binnenhaven 11, Wageningen, 6709 PD, The Netherlands.
Demirbağ
Zihni
Z
Department of Biology, Faculty of Arts and Sciences, Karadeniz Technical University, 61080, Trabzon, Turkey.
van Oers
Monique M
MM
Laboratory of Virology, Wageningen University, Binnenhaven 11, Wageningen, 6709 PD, The Netherlands.
D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000821:virology; D004259:DNA-Directed DNA Polymerase / Q000235:genetics*; D017930:Genes, Reporter; D017994:Iridovirus / Q000201:enzymology* / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins; D004259:DNA-Directed DNA Polymerase