Part:BBa_K1054002
bacteriophage PBSX holin
Holin is an essential protein for host lysis by bacteriophage. This part is cloned from Bacillus subtilis subsp. subtilis str. 168. Its activity can by blocked by another protein called lrgA (BBa_K1054024) and lrgB (BBa_K1054003). We can use this feature to prevent horizontal gene transfer of certain plasmid.
Growth curve of BL21 E.coli cells induced by different concentrations of IPTG
Contribution: iGEM22_WHU-China
WHU-China 2022 further investigated about the properties of PBSX holin. PBSX holin (Part:BBa_K1054002) is a small membrane protein in double-stranded DNA phages for efficient host lysis. Holins are the gatekeepers of the lysis process, possessing an intriguing ability to be triggered, at a precise time point, to form large holes in the cytoplasmic membrane of phage-infected bacteria. [1]
Figure. 1 Enzymatic Reaction catalyzed by opSam2
The structure is predicted by PolyPhobius prediction. It show that PBSX holin has two transmemebrane region. (figure 1. A)
A ‘death raft’ model is used to describe holin lesion formation. Th process includes accumulation and oligomerization of holins in the CM, formation of the ‘death raft’, opening of an aqueous channel and formation of the holin lesion. (figure 1. B)
We induced the expression of PBSX holin in E.coli at the log phase and measured OD. The result shows the ability of holin to inhibit the growth of bacteria to some extent.(figure 2.)
< img src="https://static.igem.wiki/teams/4144/wiki/contribution/part-bronze2.png" width="100%" height="100%">
Figure 2: A.The prediction of transmembrane domain of PBSX holin. B.The ‘death raft’ model for holin lesion formation. (Mart Krupovič, Dennis H. Bamford. 2008)
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
| n/a | bacteriophage PBSX holin |