ABSTRACT
Antiparallel beta (b) structures comprise the second large group of protein domain structures. Functionally, this group is the most diverse; it includes enzymes, transport proteins, antibodies, cell surface proteins, and virus coat proteins. The cores of these domains are built up by b strands that can vary in number from four or five to over ten. The b strands are arranged in a predominantly antiparallel fashion and usually in such a way that they form two b sheets that are joined together and packed against each other.
