Difference between revisions of "Part:BBa K4268016"

Latest revision as of 20:33, 9 October 2022

Neck and Tail Multi-Transcriptional Unit

Usage and Biology

S-TIP 37 is a T7-like cyanophage that infects its host via a lytic life cycle (Shitrit et al., 2021). T7-like phages are characterized by a complex symmetrical capsid structure, which includes an icosahedral head that houses the phage's genome, a neck region that facilitates DNA delivery into a host, and six tail fibers used for attachment to its host. (Raytcheva et al., 2011).

Figure 1: A labeled visual detailing the various structures of a T7-like phage (Kemp et al., 2005)

This part belongs to a collection that codes for a "ghost" phage. This ghost phage is a capsid-only, empty viral shell that could be modified to immobilize Cyanobacteria recognized by the viral tail fibers or used with modification to deliver substances to a chassis Cyanobacteria.

However, it will infect Synechococcus sp WH 8109, the cyanobacteria strain that is the natural host of S-TIP 37. Further modeling will be needed to determine if the "ghost" phage could effectively target other strains of Cyanobacteria that are used in synthetic biology, such as Synechococcus sp PCC 11901.

The Neck and Tail Multi-Transcriptional Unit (MTU) codes for the putative proteins that make up the neck region (Tail tubular A, B, and the Head-tail Connector Protein) and tail fibers (Tail Fiber-like Protein) of S-TIP 37. This MTU is intended to be assembled with a Capsid and Core MTU (parts BBa_K4268017 or BBa_K4268018) to create an S-TIP 37 ghost phage capsid.

The neck region in other T7 viruses serves two main purposes, binding the icosahedral capsid to the tail-like fibers and containing the molecular machinery that is responsible for injecting its contents into the target cyanobacteria. The tail fibers function in host recognition and attachment.

Sequence and Features

References

Kemp P, Garcia LR, Molineux IJ. Changes in bacteriophage T7 virion structure at the initiation of infection. Virology. 2005 Sep 30;340(2):307-17. doi: 10.1016/j.virol.2005.06.039. PMID: 16054667.

Raytcheva DA, Haase-Pettingell C, Piret JM, King JA. Intracellular assembly of cyanophage Syn5 proceeds through a scaffold-containing procapsid. J Virol. 2011 Mar;85(5):2406-15. doi: 10.1128/JVI.01601-10. Epub 2010 Dec 22. PMID: 21177804; PMCID: PMC3067778.

Shitrit D, Hackl T, Laurenceau R, Raho N, Carlson MCG, Sabehi G, Schwartz DA, Chisholm SW, Lindell D. Genetic engineering of marine cyanophages reveals integration but not lysogeny in T7-like cyanophages. ISME J. 2022 Feb;16(2):488-499. doi: 10.1038/s41396-021-01085-8. Epub 2021 Aug 24. PMID: 34429521; PMCID: PMC8776855.