Bioinformatic and biochemical characterization of helicases from Bacteriophage T5

Abstract

Bacteriophage T5 is a bacterial virus known to have a remarkably high replication rate. It is a double-stranded DNA virus and encodes many of the proteins needed for its own replication. During replication, the viral double-stranded genomic DNA has to be separated by enzymes called helicases, which are motor proteins that utilize chemical energy from ATP to move along and unwind nucleic acid duplexes. Until now, no helicase has been characterized in bacteriophage T5. A bioinformatic analysis on the T5 replication gene cluster showed that several early gene products (D2, D6 and D10), which possess key helicase signature sequences (motifs), may be T5 helicases. This is the first report to investigate helicases of bacteriophage T5 and the study focused on bioinformatic and biochemical characterization of these three potential helicases. Here, D2 and D10 were identified to be two novel T5 helicases, showing helicase activity in vitro as well as having some unique properties previously uncharacterised in other helicases. However, D6 did not show ATPase activity under the condition employed and a further investigation on characteristics of D6 is required.