User:Ridaxahmed/Curli

Lead
Amyloid is associated with human neurodegenerative diseases such as Alzheimer's disease, Huntington's disease, Parkinson's disease, and prion diseases.

Article body
Curli fibers, and thus the curli protein, are coded by two divergently-transcribed operons in E. coli: the csgBAC and csgDEFG operons. In total, these operons encode at least seven proteins. The agfBA and agfDEFG operons, which have been identified in Salmonella spp., are homologous to the csgBAC and csgDEFG operons.

Without the presence of the R5 subunit, or the changes within the subunit, CsgA is secreted from the cell in an unpolymerized form and cannot properly form on cell surfaces.

A convenient way to identify genes important for curli production is by growing curliated bacteria on plates supplemented with Congo red diazo dye, causing a red shift.

However, it is now known that curli expression is strain- and condition-specific. For example, mutations to the CsgD promoter can result in curli expression at 37°C.