Site directed DNA joining

We have previously identified a cDNA encoding part of the amino terminal portion of the large subunit of replication factor c (RF-C, AP-1), which we have named VDJP. Analysis of VDJP demonstrated that it has amino acid homology to bacterial DNA ligases and specific binding to the nonamer portion of the V(D)J recombination signal sequence motif. In this report, we demonstrate that VDJP is capable of forming a covalent bond between DNA fragments in a sequence dependent fashion. The VDJP mediated DNA ligation reaction is neither dependent on the presence of compatible DNA ends nor on sequence homology between the DNA fragments that are joined. Furthermore, we show that the covalent junction between the DNA fragments is resistant to proteases and phenol, and therefore not protein linked.