An example of self-connection case for domain swapping proteins of 1a2w:A and 5rsa:A. The yellow part of open-form Ribonuclease A (PDB code: 1a2w, chain A) swaps toward the protein body to form a closed-form (PDB code: 5rsa, chain A). (a) The structural alignment of 1a2w:A (green) and 5rsa:A (blue); the hinge loops are highlighted in red. The backbone surfaces of 1a2w: A (b) and 5rsa:A (c) are different due to domain swapped and self-connected formation. However, LADED(d) and LADGD(e) profiles for both structures remain consistent.