CIRCULAR PERMUTATIONS OF NATURAL PROTEIN SEQUENCES - STRUCTURAL EVIDENCE

Over the past few years, evidence has accumulated that shows that circ ularly permuted proteins resulting from permutations in their coding g enes can indeed occur naturally. In most instances, these circularly p ermuted amino acid sequences have been detected by sequence alignment of homologous proteins. Circular permutations may escape detection, ho wever, when based on sequence comparisons alone, as recently illustrat ed by transaldolase, a member of the class I aldolase family. (C) Curr ent Biology Ltd.