Bipartite DNA-binding region of the Epstein-Barr virus BMRF1 product essential for DNA polymerase accessory function.
AUTOR(ES)
Kiehl, A
RESUMO
The Epstein-Barr virus (EBV) BMRF1 gene product is necessary for DNA polymerase catalytic subunit (BALF5) activity in 100 mM ammonium sulfate. To map regions of BMRF1 necessary for polymerase accessory function, linker insertion and deletion mutant BMRF1 polypeptides were expressed by in vitro transcription-translation and assayed for DNA polymerase elongation activity and binding to double-stranded DNA (dsDNA)-cellulose. Amino-terminal deletions up to residue 303 were defective for stimulation of elongation. Deletions between residues 44 and 194 and residues 238 and 303 abolished binding to dsDNA-cellulose. The region from residues 194 to 238, therefore, is necessary for stimulation of BALF5 elongation but dispensable for dsDNA-cellulose binding. Deletion analysis also localized reactive epitopes of two neutralizing monoclonal antibodies to BMRF1 to a carboxy-terminal region which is dispensable for activity. These data suggest that a bipartite DNA-binding region is an essential component of the DNA polymerase accessory function and that the two noncontiguous regions are separated by a region (residues 194 to 217) which is essential for stimulation; therefore, it may interact with the BALF5 catalytic subunit of EBV DNA polymerase. Both EBV BMRF1 and herpes simplex virus UL42 gene products are DNA polymerase accessory proteins which bind dsDNA and increase the processivity of their corresponding catalytic components. Outstanding similarities between their primary amino acid sequences are not evident. However, it appears that their structural organizations are similar.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=188766Documentos Relacionados
- Purification and characterization of the DNA-binding activity of the Epstein-Barr virus DNA polymerase accessory protein BMRF1 gene products, as expressed in insect cells by using the baculovirus system.
- The Epstein-Barr Virus Protein BMRF1 Activates Gastrin Transcription
- High-resolution footprints of the DNA-binding domain of Epstein-Barr virus nuclear antigen 1.
- Direct BRLF1 binding is required for cooperative BZLF1/BRLF1 activation of the Epstein–Barr virus early promoter, BMRF1
- Characterization of the DNA-binding site repertoire for the Epstein-Barr virus transcription factor R.