Folding initiation sites and protein folding

The paper discusses the role of local structural preferences of protein seg ments in the folding of proteins. First a short overview of the local, seco ndary structures detected in peptides, protein fragments, denatured protein s and early folding intermediates is given. Next the discussion of their ro le in protein folding is presented based on recent literature and data obta ined in our laboratory. In conclusion it is pointed out that, during foldin g, local structures populated at low levels in denatured state may facilita te the crossing of the folding transition state barrier, and consequently a ccelerate the rate limiting step in folding. However, the data show that th is effect does not follow simple rules.