Se. Brenner et al., POPULATION STATISTICS OF PROTEIN STRUCTURES - LESSONS FROM STRUCTURALCLASSIFICATIONS, Current opinion in structural biology, 7(3), 1997, pp. 369-376
Structural classifications aid the interpretation of proteins by descr
ibing degrees of structural and evolutionary relatedness. They have al
so recently revealed strikingly skewed distributions at all levels; fo
r example, a small number of folds are far more common than others, an
d just a few superfamilies are known to have diverged widely. The clas
sifications also provide an indication of the total number of superfam
ilies in nature. (C) Current Biology Ltd.