Source:
Generated By: https://synbiohub.org/public/igem/igem2sbol/1
Created by: Aaditya Shidham
Date created: 2010-06-05 11:00:00
Date modified: 2015-05-08 01:14:02
L28H-fnr CDS
| Types | DnaRegion |
| Roles | CDS Coding |
| Sequences | BBa_M33356_sequence (Version 1) |
Description
Long description:fnr (fumarate nitrate reductase) is a DNA-binding protein that is a global regulator involved in cellular respiration and metabolism during times of anaerobic cell growth (Melville et al 1996). As an iron-sulfur protein, however, fnr depends on its [4Fe-4S][+2] cluster to have functional ability in the cell. Upon exposure to oxygen, fnr undergoes a "rapid [4Fe-4S][+2] to [2Fe-2S][+2] cluster conversion...[and a] concomitant loss in site-specific DNA binding and dimerization" (Bates et al 2000), which results in fnr losing its acitvity in the cell in aerobic conditions.However, a substitution of Histidine on the 28th amino acid of fnr (which is Leucine in the WT [wildtype] fnr) results in a protein that is functional in aerobic growth conditions. The new mutant protein is called L28H-fnr in the literature. It is suggested that this added functionality of L28H-fnr occurs because the "His-28 substitution appears to stabilize the [4Fe-4S][+2] cluster of FNR-L28H in the presence of O2" (Bates et al 2000). The part's resistance to oxygen has allowed it to be used for more practical biosensors that can work in oxygen environments to "enable nitrate-dependent expression"(Li, Rabi, DeMoss 1985).
Notes
No RBS (ribosome binding sites) were included in the detailed design of the sequence. This is because it would constrain the user of this piece to only one RBS when this fnr* gene would be used. Also, the addition of the TAATAA at the end of the CDS at this piece would force a stop to the translation.Source
This part was directly copied from a genomic sequence--specifically from the EcoGene DNA database (ecogene.org). The selection was from 111 bp upstream of fnr CDS (coding sequence), to the end of the CDS.Afterward, the following edits were made: the last ten base-pairs before the CDS were deleted as they were part of the RBS (ribosome binding site) of the fnr (Shaw, Guest 1982). Also, the required Leucine to Histidine switch was made in the CDS. Finally, the sequence TAATAA replaced the last three nucleotides of the coding sequence.