PMID:24711378

Citation	Kala, S, Cumby, N, Sadowski, PD, Hyder, BZ, Kanelis, V, Davidson, AR and Maxwell, KL (2014) HNH proteins are a widespread component of phage DNA packaging machines. Proc. Natl. Acad. Sci. U.S.A. 111:6022-7
Abstract	The genome packaging reactions of tailed bacteriophages and herpes viruses require the activity of a terminase enzyme, which is comprised of large and small subunits. Phage genomes are replicated as linear concatemers composed of multiple copies of the genome joined end to end. As the terminase enzyme packages the genome into the phage capsid, it cleaves the DNA into single genome-length units. In this work, we show that the phage HK97 HNH protein, gp74, is required for the specific endonuclease activity of HK97 terminase and is essential for phage head morphogenesis. HNH proteins are a very common family of proteins generally associated with nuclease activity that are found in all kingdoms of life. We show that the activity of gp74 in terminase-mediated cleavage of the phage cos site relies on the presence of an HNH motif active-site residue, and that the large subunit of HK97 terminase physically interacts with gp74. Bioinformatic analysis reveals that the role of HNH proteins in terminase function is widespread among long-tailed phages and is uniquely required for the activity of the Terminase_1 family of large terminase proteins.
Links	PubMed PMC4000778 Online version:10.1073/pnas.1320952111
Keywords	Amino Acid Sequence; Bacteriophages/physiology; Bacteriophages/ultrastructure; Catalytic Domain; Circular Dichroism; DNA Packaging; Endodeoxyribonucleases/metabolism; Escherichia coli/virology; Histidine/metabolism; Molecular Sequence Data; Protein Binding; Protein Subunits/metabolism; Viral Proteins/chemistry; Viral Proteins/metabolism; Virus Assembly
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
BPHK7:Q9MCN1		GO:1905138: positive regulation of viral DNA genome packaging via site-specific sequence recognition	ECO:0000314:		P		Inferred from figure 1 and 2 for regulation of DNA virion packing.	complete CACAO 11934

References

See Help:References for how to manage references in GONUTS.