Part:BBa_K1632020

rbs_CmR(ssrA degradation tag)

In our project, we wanted to use the CmR. At the first stage of wet experiment, we used the cells which have the plasmid which is Pcon_rhlR_TT_Plux_rbs_CmR(Fig. 1.) to characterize the function of rbs_CmR(BBa_K395160 by iGEM10_Tokyo_Tech). But the cells showed active growth even in the absence of AHL (Fig. 2.)

Fig. 1.Our initially design of a part containing a previously existing part

Fig. 2. The cells growth with Cm

From the results of this experiment, initially designed circuits showed leaky expression of CmR. We came up with two solutions, either increasing the chloramphenicol (Cm) concentration or inserting an ssrA tag to the CmR gene, to this problem. From modeling allowed us to successfully solve the influence of the leakage by adding an ssrA degradation tag right after the CmR gene(Fig.3.).

Fig. 3. The results of modeling

Fig. 4. The cells which have BBa_K1632022 growth with Cm

Fig. 5. The cells which have BBa_K1632023 growth with Cm

In the experiment using the Pcon_lasR_TT_Plux_CmRssrA (BBa_K1632022) (Fig.4.) and Pcon_rhlR_TT_Plux_CmRssrA (BBa_K1632023) (Fig.5.), we could not observe cell growth for cells that owned the ssrA-taged plasmid, in the absence of AHL
From our experiment, CmRssrA is confirmed work better than CmR without ssrA tag for our project.

For more information, see [http://2015.igem.org/Team:Tokyo_Tech/Project our work in Tokyo_Tech 2015 wiki].

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]