RT Journal Article SR Electronic(1) A1 Hafner, Gregory J A1 Stafford, Mark R A1 Wolter, Lindsay C A1 Harding, Robert M A1 Dale, James LYR 1997 T1 Nicking and joining activity of banana bunchy top virus replication protein in vitro. JF Journal of General Virology, VO 78 IS 7 SP 1795 OP 1799 DO https://doi.org/10.1099/0022-1317-78-7-1795 PB Microbiology Society, SN 1465-2099, AB The major open reading frame of banana bunchy top virus (BBTV) DNA-1 encodes a putative replication initiation protein (Rep). In vitro, a fusion protein of BBTV Rep linked to a maltose-binding protein exhibited both site-specific nicking and joining activities. These activities were dependent on the presence of Mg2 or Mn2 , but did not require ATP. The fusion protein specifically cleaved ssDNA between bases 7 and 8 of a conserved nonanucleotide loop sequence which is present in the virion-strand of the stem-loop common region of each BBTV component. During this reaction, the fusion protein became covalently attached to the 5′ end of the 3 cleavage product. After the nicking reactions, the fusion protein was also capable of catalysing the joining of two nicked ssDNA fragments in a site-specific manner. Based on these activities, BBTV Rep would appear to be very similar to the Rep proteins of the geminiviruses., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-78-7-1795