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Protein chainmail variants in dsDNA viruses
- Source :
- AIMS Biophysics, Vol 2, Iss 2, Pp 200-218 (2015)
- Publication Year :
- 2015
- Publisher :
- AIMS Press, 2015.
-
Abstract
- First discovered in bacteriophage HK97, biological chainmail is a highly stable system formed by concatenated protein rings. Each subunit of the ring contains the HK97-like fold, which is characterized by its submarine-like shape with a 5-stranded β sheet in the axial (A) domain, spine helix in the peripheral (P) domain, and an extended (E) loop. HK97 capsid consists of covalently-linked copies of just one HK97-like fold protein and represents the most effective strategy to form highly stable chainmail needed for dsDNA genome encapsidation. Recently, near-atomic resolution structures enabled by cryo electron microscopy (cryoEM) have revealed a range of other, more complex variants of this strategy for constructing dsDNA viruses. The first strategy, exemplified by P22-like phages, is the attachment of an insertional (I) domain to the core 5-stranded β sheet of the HK97-like fold. The atomic models of the Bordetella phage BPP-1 showcases an alternative topology of the classic HK97 topology of the HK97-like fold, as well as the second strategy for constructing stable capsids, where an auxiliary jellyroll protein dimer serves to cement the non-covalent chainmail formed by capsid protein subunits. The third strategy, found in lambda-like phages, uses auxiliary protein trimers to stabilize the underlying non-covalent chainmail near the 3-fold axis. Herpesviruses represent highly complex viruses that use a combination of these strategies, resulting in four-level hierarchical organization including a non-covalent chainmail formed by the HK97-like fold domain found in the floor region. A thorough understanding of these structures should help unlock the enigma of the emergence and evolution of dsDNA viruses and inform bioengineering efforts based on these viruses.
Details
- Language :
- English
- ISSN :
- 23779098
- Volume :
- 2
- Issue :
- 2
- Database :
- Directory of Open Access Journals
- Journal :
- AIMS Biophysics
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.b5ec1b7e44ad08b215152a4b0d9d0
- Document Type :
- article
- Full Text :
- https://doi.org/10.3934/biophy.2015.2.200