Part:BBa_K2912000

RebA may act as a scaffolding protein to facilitate the major polymerization process

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. It has been suggested that RebA may act as a scaffolding protein to facilitate the major polymerization process.The identity in amino acid sequence between RebA and RebB suggests a similar structure and function. Like RebB, RebA is modified into two or more species with different molecular weights before the major polymerization event occurs.

Comparison of the hydropathy plots for RebB with those for RebA suggests a similar secondary structure for these regions. Therefore, RebA should be capable of entering into either a temporary or permanent association with the polymerized complexes of RebB. If the acidic RebA proteins are linked to the growing R body complex (as scaffolding or at the site of polymerization), they may be responsible for the increased pIs during the major polymerization event. That is, the proportional contribution of RebA may decline as polymerization proceeds, resulting in a shift of the pls. Pulse-chase analysis of the protein products encoded by pBQ65 reveals that, like RebB, the modified faster-migrating species of RebA decrease in concentration over time as the higher-molecular-weight polymerization complexes are formed. This is evidence that RebA proteins may associate directly with the polymerization complexes.

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]