The development of areas of protein called amyloid plaques is one of the most distinctive features of Alzheimer's disease and other similar neuropathies. In 1 February Science, Matthew Chapman and colleagues at the Washington University School of Medicine, St. Louis reported that certain strains of Escherichia coli bacteria also produce amyloid fibers called curli (Science 2002, 295:851-855).

Chapman et al. examined curli production in E. coli and identified two proteins involved in the process — CsgA and CsgB. The CsgA protein is released into the extracellular environment surrounding the bacterium with CsgB associated with the bacterial cell wall. In the same way as a particle of dust acts as the initiator in snowflake formation, the CsgB protein nucleates the precipitation of CsgA out of solution and subsequent fiber formation. The formation of the meshwork of curli is an integral part of the development of biofilm...