DinG is an Escherichia coli DNA damage-inducible gene (1, 2). Sequence database searches (3, 4) revealed marginally significant similarities between the 637 amino acid DinG protein, yeast DNA helicases Chll, Rad3 and Rad 15, and the human helicase ERCC2. Remarkably, the similarities included some of the motifs conserved in the 'DExD/H' helicase superfamily (5). However, DinG sequence did not co...

In the trypsin superfamily of serine proteases, non-trypsin-like primary specificities have arisen in only two monophyletic descendent subbranches. We have recreated an ancestor to one of these subbranches (granzyme) using phylogenetic inference, gene synthesis, and protein expression. This ancestor has two unusual properties. First, it has broad primary specificity encompassing the entire repe...

The TGF-β (transforming growth factor-β) cytokine superfamily in mammals contains some 30 members. These dimeric proteins are characterized by a strongly conserved cystine knot-based structure. They regulate the proliferation, differentiation and migration of many cell types, and therefore have important roles in morphogenesis, organogenesis, tissue maintenance and wound healing. Thus far, arou...

Crystallins which form the major protein components of the eye lens are responsible for its transparency. βγ-crystallin superfamily has a well-characterized protein fold which is present in several members in prokaryotes and eukaryotes. Apart from two members from eukaryote, Spherulin 3a and Ciona crystallin, a majority of them possess the two or more βγ-crystallin domains. The βγ domain consis...