DECIPHERING PROTEIN-SEQUENCE INFORMATION THROUGH HYDROPHOBIC CLUSTER-ANALYSIS (HCA) - CURRENT STATUS AND PERSPECTIVES

Ten years after the idea of hydrophobic cluster analysis (HCA) was con ceived and first published, theoretical and practical experience has s hown this unconventional method of protein sequence analysis to be par ticularly efficient and sensitive, especially with families of sequenc es sharing low levels of sequence identity. This extreme sensitivity h as made it possible to predict the functions of genes whose sequence s imilarities are hardly if at all detectable by current one-dimensional (1D) methods alone, and offers a new way to explore the enormous amou nt of data generated by genome sequencing. HCA also provides original tools to understand fundamental features of protein stability and fold ing. Since the last review of HCA published in 1990 [1], significant i mprovements have been made and several new facets have been addressed. Here we wish to update and summarize this information.