Source:
Generated By: https://synbiohub.org/public/igem/igem2sbol/1
Created by: Choi Yan Ru
Date created: 2016-10-08 11:00:00
Date modified: 2016-10-10 03:37:25
HasA hemophore expression unit
| Types | DnaRegion |
| Roles | Signalling engineered_region |
| Sequences | BBa_K1897001_sequence (Version 1) |
Description
The HasA hemophore (19 kDa monomer) is originally from the Serratia marcescens and used in their heme uptake pathway. When bound to heme, the HasA hemophore is able to trigger expression of genes through the Has system. The heme-bound HasA hemophore is able to bind to a membrane receptor HasR, a component of the signalling cascade that regulates expression of the genes in the has operon via HasS and HasI. When HasR is activated, it causes a conformation change in HasS, an anti-sigma factor. This causes the release of the sigma factor, HasI, initially bound to it. HasI then goes on to bind to a specific promoter to trigger expression of genes under the control of that promoter. This is a composite part created from the coding sequence of HasA (BBa K1897000) with the addition of Bba_K525998, which contains a promoter and Ribosome Binding Site (RBS), and Bba_B0015, which contains a double terminator. The addition of these parts make BBa K1897001 a functional unit that can be used for expression, unlike BBa K1897000 which lacks the promoter, RBS and terminator and hence cannot be used on its own for expression.Notes
The presence of a hexa histidine tag would allow for easy protein purification and detection using anti-his antibodies. The promoter BBa_K525998 was chosen as we wished to induce high levels of HasA for purification thus we required a T7 promoter that could be used to induce expression at high levels in E. coli strain BL21(DE3). The terminator BBa_B0015 was chosen as it is commonly used and has a high efficacy.Source
The HasA coding sequence is originally found in the Serratia marcescens and to construct this part, we used the HasA gene that is from the part BBa K1897000 which was synthesised based on the gene sequence from the National Center for Biotechnology Information (NCBI) database (http://www.ncbi.nlm.nih.gov/nuccore/X81195.2). The Promoter, RBS and terminator are biobrick parts that were obtained from the Distribution kits from iGEM.| Access | Instance | Definition |
| public public public | BBa_K525998 BBa_K1897000 BBa_B0015 | pT7 BBa_K1897000 BBa_B0015 |
| Sequence Annotation | Location | Component / Role(s) |
| BBa_K525998 BBa_K1897000 BBa_B0015 | 1,32 39,623 632,760 | pT7 BBa_K1897000 BBa_B0015 |