The small terminase, gp16, of bacteriophage T4 is a regulator of the DNA packaging motor.

ABSTRACT: Tailed bacteriophages and herpes viruses use powerful molecular motors to translocate DNA into a preassembled prohead and compact the DNA to near crystalline density. The phage T4 motor, a pentamer of 70-kDa large terminase, gp17, is the fastest and most powerful motor reported to date. gp17 has an ATPase activity that powers DNA translocation and a nuclease activity that cuts concatemeric DNA and generates the termini of viral genome. An 18-kDa small terminase, gp16, is also essential, but its role in DNA packaging is poorly understood. gp16 forms oligomers, most likely octamers, exhibits no enzymatic activities, but stimulates the gp17-ATPase activity, and inhibits the nuclease activity. Extensive mutational and biochemical analyses show that gp16 contains three domains, a central oligom

SUBMITTER: Al-Zahrani AS 

PROVIDER: S-EPMC2782041 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature