Part:BBa_K2912001

The major structural subunit of R bodies-RebB

2019 SZZU-China

Biology

SZU-China 2019 iGEM team was going to find a suicide switch inside the E coli that can break the whole body of the bacteria leading to the release of RNAi molecules transcribed from E coli inducing by IPTG or some other else. Therefore, we were in need of a useful mechanism. Fortunately, we finally found the Refractile inclusion bodies (R-bodies) to kill the E coli, causing the inclusion to flow out of the plasma membrane so that we can get the RNAi molecules transcribed by E coli.

Refractile inclusion bodies, known as R bodies, are produced by only a few species of bacteria. These inclusion bodies are highly insoluble protein ribbons, typically seen coiled into cylindrical structures within the cell. R-bodies are produced by Paramecium endosymbionts belonging to the genus Caedibacter. These intracellular bacteria confer upon their hosts a phenomenon called the killer trait. This is one of the DNA sequences for the R body locus (reb) from Caedibacter taeniospiralis.

Reb B appears to be the major structural subunit of R bodies. There're 12 species of RebB can be identified and Reb B has two molecular weights, each with six isoelectric points. Compared to Reb A and Reb C, The DNA sequence-based prediction that RebB is neutral was confirmed by observed migration of the polypeptides in isoelectric focusing gels. Although All three(Reb A, Reb B, Reb C) proteins are required for the major polymerization event, only RebB and RebC are necessary for the basic polymerization process.

The R bodies of C. taeniospiralis are type 51. They are about 0.5 μm wide, have a maximum length of 20 μm, and 13 nm thick, possess acute angles at each end and unroll in a telescopic fashion when exposed to a pH of 6.5 or lower. These proteinaceous ribbons are rolling up inside the cell to form a hollow cylinder about 0.5 μm in diameter and 0.5 μm long[4]. For more information, please see BBa_K2912017-R-body.

Sequence

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]