Escherichia virus HK97 explained
Escherichia virus HK97, often shortened to HK97, is a species of virus that infects Escherichia coli and related bacteria. It is named after Hong Kong (HK), where it was first located. HK97 has a double-stranded DNA genome.
Assembly and maturation
The major capsid protein of HK97, called gp5, cross-links upon maturation to form a chain-mail like structure.[1] While DNA is being packaged into the capsid, the capsid expands by nearly 5 nm and changes from spherical to icosahedral in shape.
The HK97 assembly pathway begins with self-assembly of gp5 into pentamers and hexamers. A protease, called gp4, cleaves gp5 at its N-terminus. Attachment of a portal protein, gp3, coupled with conformational changes leads to the formation of a prohead, or procapsid, which is the precursor to the mature capsid.[2] A scaffolding protein is not required for capsid assembly.[3] However, studies on the effects of deleting the delta domain of the major capsid protein, or parts of it, indicate that it is essential for assembly.[4]
Further reading
External links
Notes and References
- Helgstrand. Charlotte. Wikoff, William R . Duda, Robert L . Hendrix, Roger W . Johnson, John E . Liljas, Lars . The Refined Structure of a Protein Catenane: The HK97 Bacteriophage Capsid at 3.44Å Resolution. Journal of Molecular Biology. 1 December 2003. 334. 5. 885–899. 10.1016/j.jmb.2003.09.035. 14643655.
- Book: Hendrix, RW. Johnson, JE. Viral Molecular Machines . Bacteriophage HK97 Capsid Assembly and Maturation . Advances in Experimental Medicine and Biology . 2012. 726. 351–63. 22297521. 10.1007/978-1-4614-0980-9_15. 978-1-4614-0979-3.
- Duda RL, Martincic K, Hendrix RW . Genetic basis of bacteriophage HK97 prohead assembly . J. Mol. Biol. . 247 . 4 . 636–47 . 1995 . 7723020 . 10.1006/jmbi.1994.0169 .
- Oh B, Moyer CL, Hendrix RW, Duda RL . The delta domain of the HK97 major capsid protein is essential for assembly . Virology . 456-457 . 171–8 . 2014 . 24889236 . 4044616 . 10.1016/j.virol.2014.03.022 .
