期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1977
卷号:74
期号:5
页码:1841-1845
DOI:10.1073/pnas.74.5.1841
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Vaccinia virus cores contain an activity which is able to relax both left-and right-handed superhelical DNA. This virus-specific nicking closing enzyme has been highly purified and differs from the corresponding host enzyme in salt optimum, in sedimentation coefficient, and in polypeptide composition as determined on sodium dodecyl sulfate/polyacrylamide gels. The enzyme is probably newly synthesized after the cessation of host protein synthesis which follows virus infection. The most highly purified preparation contains two polypeptides, one of molecular weight 24,000 and the other 35,000. The former polypeptide is a major constituent of the virus (7% of total protein by weight), whereas the latter is present in a much smaller amount (0.2%). Chromatography with denatured DNA-cellulose reveals that the activity is predominately associated with those fractions enriched in the polypeptide of greater molecular weight.