ABSTRACT
In each of the pairs of related proteins, however, both distal and proximal local sequences are more closely related to one another than to any of the other local sequences. Immunoglobulins at first appeared to be ideal candidates to yield answers to all the issues at once, since domains were first defined in Ig molecules. Shortly after the discovery that many eukaryotic genes are complex, with non-coding DNA interspersed among the coding regions, W. Gilbert, C. F. Blake and J. E. Darnell independently hypothesized that the exons of structural genes code domains within the larger polypeptides. Before proceeding to a concluding discussion of the domain-like characteristics of the heme-binding site and its relationship to a particular genetic element, it is profitable to discuss recent results of an investigation of the kinetics of refolding of human a-globin induced by heme binding.
