Difference between revisions of "Part:BBa K2912002"

Revision as of 11:38, 11 October 2022

RebC may be involved in the modification process of forming the R bodies

2019 SZU-China

Biology

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 C may be involved in the modification process. Either methylation or the trimming of terminal amino acids would result in a change of migration within an SDS-polyacrylamide gel. The migration of these polypeptides does not reflect their predicted sizes, and anomalous migration patterns are seen when these polypeptides are electrophoresed in gels with different percentages of acrylamide, making it difficult to assess which processes might be involved in generating species with different molecular weights. A polypeptide as small as reb C is probably not capable of carrying out such posttranslational functions itself, but, by binding to rebA or rebB, it may induce conformational changes that allow host proteins to modify the proteins.

Reb C is also necessary for the modification of rebB into six species with different pI values. At each stage of the polymerization process，there are several species differing in pl. The type of posttranslational modification involved is unknown. Phosphorylation of the numerous Ser and Thr residues in rebB would result in different pIs. It is possible that as the subunits polymerize, the modified acidic residues are blocked by folding or are involved in the covalent linkages themselves. Thus, as polymerization proceeds, the R body complex becomes increasingly basic. Moreover, rebC and rebB are necessary for the basic polymerization process. For more information, please see BBa_K2912017-R-body.

Sequence

Sequence and Features