'Multifrequency' location and clustering of sequence patterns from proteins

In previous work, we have shown that a set of characteristics,defined as (code frequency) pairs, can be derived from a proteinfamily by the use of a signal-processing method. This methodenables the location and extraction of sequence patterns bytaking into account each (code frequency) pair individually.In the present paper, we propose to extend this method in orderto detect and visualize patterns by taking into account severalpairs simultaneously. Two ‘multifrequency’ methodsare described. The first one is based on a rewriting of thesequences with new symbols which summarize the frequency information.The second method is based on a clustering of the patterns associatedwith each pair. Both methods lead to the definition of significantconsensus sequences. Some results obtained with calcium-bindingproteins and serine proteases are also discussed. Received on March 6, 1990; accepted on September 24, 1990