  In the present work, we review the fundamental methods which have been
developed in the last few years for classifying into families and clans the
distribution of amino acids in protein databases. This is done through
functions of random variables, the Entropy Measures of probabilities of
occurrence of the amino acids. An intensive study of the Pfam databases is
presented with restrictions to families which could be represented by
rectangular arrays of amino acids with m rows (protein domains) and n columns
(amino acids). This work is also an invitation to scientific research groups
worldwide to undertake the statistical analysis with different numbers of rows
and columns since we believe in the mathematical characterization of the
distribution of amino acids as a fundamental insight on the determination of
protein structure and evolution.
