Difference between revisions of "Part:BBa K3093000"

Revision as of 11:41, 21 October 2019

chbR N238S Y30C

"Chitobiose regulator," ChbR, is a dual transcriptional factor that regulates an operon (chb) involved in transport and degradation of the -glucoside N,N'-diacetylchitobiose (chitobiose) . [More information is available at EcoCyc: EG10143].

Usage and Biology

ChbR is encoded within the chb operon itself. In the presence of chitobiose, ChbR binds to two direct repeats located between two NagC binding sites and activates the transcription of the chb operon by overlapping the -35 box of chbBp. In the absence of chitobiose, ChbR acts as a repressor of the chb operon. Monoacetylchitobiose-6-P has been experimentally determined to be the inducer for ChbR.

The sequence of chbR was obtained from E.coli K12 MG1655 via PCR.Then we performed inverse PCR to achieve the site-directed mutation of amino acids of chbR. According to the literature, we chose three site-directed mutation : ChbR N238S;ChbR Y30C; ChbR N137K.

Figure 1. The site-directed mutation of ChbR N238S

Figure 2. The site-directed mutation of ChbR Y30C

Figure 3. The site-directed mutation of ChbR N137K

References

[1]Plumbridge J, Pellegrini O. Expression of the chitobiose operon of Escherichia coli is regulated by three transcription factors: NagC, ChbR and CAP. Mol Microbiol. 2004 Apr;52(2):437-49. PubMed PMID: 15066032.

[2]Kachroo AH, Kancherla AK, Singh NS, Varshney U, Mahadevan S. Mutations that alter the regulation of the chb operon of Escherichia coli allow utilization of cellobiose. Mol Microbiol. 2007 Dec;66(6):1382-95. Epub 2007 Nov 19. PubMed PMID: 18028317.

Sequence and Features

Sequence and Features