Types | DnaRegion
|
Roles | Regulatory
promoter
|
Sequences | BBa_K851005_sequence (Version 1)
|
Description
CzrA/ArsR(1)
CzrA/ArsR(1) is a combination of two different metal sensor systems already present in Bacillus Subtilis. It was made with the combined ArsR binding site and CadA promoter.
It is a variation of Biobrick Part:BBa_K174015[1] first proposed by Newcastle 2009 iGEM team [2] for the construction of a cadmium sensor[3] and also designed in with the combination of ArsR binding site (Part:BBa_K174016)[4] and cadA promoter (Part:BBa_K174017)[5]. The improvement made by our team is the modification of the ArsR binding site for a better repression of the promoter through steric impediment of the sigma factor binding to the -35 box.
For iGEM UNAM Genomics M??xico 2012 project [6], CzrA/ArsR(1) was used in the design of an AND logic gate[7] using a recently described new type of communication system between Bacillus Subtilis cells called Nanotubes[8]. We synthetized three alternative forms of this part: which can be found here and in (PART CzrA/ArsR-Newcastle 2009)[1]and PART CzrA/ArsR-2(UNAM_Genomics 2012)[ 9].
BIOLOGY
In B. subtilis, ArsR has been shown to de-repress arsenical stress response genes of the ars operon in response to As(III) and Sb(III) [10](Sato and Kobayashi, 1998). It also has been shown to respond to Cd(II) and Ag(I) stress[11].
ArsR/SmtB family metalloregulators negatively regulate genes involved with metal efflux [12]. Binding of inducers to one of (at least) two distinct metal binding sites triggers de-repression. ArsR negatively regulates itself, a gene of unknown function (yqcK) and genes encoding an As(III) efflux pump (arsB) and an As(V) reductase (arsC) [10,13].
CzrA (formerly YozA in Bacillus subtilis), an ArsR homolog, represses two metal efflux systems [11] which are induced in response to several metals (Zn(II), Cd(II), Co(II) and Ni(II) and weakly to Cu(II))[13]. Specifically, CzrA represses the CadA efflux ATPase and the cation diffusion facilitator CzcD. CzrA has the unusual ability to respond to both thiophilic metals and Zn(II), Co(II) and Ni(II).
Notes
steric impediment of the sigma factor binding to the -35 box
Source
REFERENCES
[1] http://partsregistry.org/Part:BBa_K174015
[2] http://2009.igem.org/Team:Newcastle
[3]http://2009.igem.org/Team:Newcastle/Metalsensing
[4] http://partsregistry.org/Part:BBa_K174016
[5] http://partsregistry.org/Part:BBa_K174017
[6] http://2012.igem.org/Team:UNAM_Genomics_Mexico
[7] http://2012.igem.org/Team:UNAM_Genomics_Mexico/Project/Description
[8] Dubey GP, Ben-Yehuda S. (2011) Intercellular nanotubes mediate bacterial communication. Cell.;144(4) :590-600
[9] http://partsregistry.org/Part:BBa_K851006
[10] Sato, T., and Kobayashi, Y. (1998) The ars operon in the skin element of Bacillus subtilis confers resistance to arsenate and arsenite. J Bacteriol 180: 1655???1661.
[11] Moore CM, Gaballa A, Hui M, Ye RW, Helmann JD (2005). Genetic and physiological responses of Bacillus subtilis to metal ion stress. Mol Microbiol(1) , 27???40.
[12] Busenlehner LS, Pennella MA, Giedroc DP (2003). The SmtB/ArsR family of metalloregulatory transcriptional repressors: Structural insights into prokaryotic metal resistance. FEMS Microbiol Rev , 27:131-143.
[13] Charles M Moore and John D Helmann(2005). Metal ion homeostasis in Bacillus subtilis. Current Opinion in Microbiology, 8:188???195.