tailieunhanh - báo cáo hóa học:" Origin-independent plasmid replication occurs in vaccinia virus cytoplasmic factories and requires all five known poxvirus replication factors"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Origin-independent plasmid replication occurs in vaccinia virus cytoplasmic factories and requires all five known poxvirus replication factors | Virology Journal BioMed Central Research Open Access Origin-independent plasmid replication occurs in vaccinia virus cytoplasmic factories and requires all five known poxvirus replication factors Frank S De Silva and Bernard Moss Address Laboratory of Viral Diseases National Institute of Allergy and Infectious Diseases National Institutes of Health Bethesda Maryland 20892-0445 USA Email Frank S De Silva - fdesilva@ Bernard Moss - bmoss@ Corresponding author Published 22 March 2005 Received 10 March 2005 Accepted 22 March 2005 Virology Journal 2005 2 23 doi l743-422X-2-23 This article is available from http content 2 1 23 2005 De Silva and Moss licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Replication of the vaccinia virus genome occurs in cytoplasmic factory areas and is dependent on the virus-encoded DNA polymerase and at least four additional viral proteins. DNA synthesis appears to start near the ends of the genome but specific origin sequences have not been defined. Surprisingly transfected circular DNA lacking specific viral sequences is also replicated in poxvirus-infected cells. Origin-independent plasmid replication depends on the viral DNA polymerase but neither the number of additional viral proteins nor the site of replication has been determined. Results Using a novel real-time polymerase chain reaction assay we detected a 400-fold increase in newly replicated plasmid in cells infected with vaccinia virus. Studies with conditional lethal mutants of vaccinia virus indicated that each of the five proteins known to be required for viral genome replication was also required for plasmid replication. The intracellular site of replication was .