(a) N matrix of the phenylalanyl-tRNA syhthetase (1jjc) chain B (contour map) where N_ij is the number of pLSSP in which residues i and j of the query protein are found together. This chain consists of six domains. For instance, SMF algorithm finds the following domains: D1: (1–41, 151–196), D2: (42–150), D3: (197–398), D4: (399–484), D5: (485–676), D6: (677–785). Note that D1 is a segmented domain as defined in CATH and SCOP. This matrix made of several ten of thousands pLSSPs, gives a global view of the recurrence and of the domain organization. (b) An example of aligned structural neighbors for 1jjc chain B, sorted by decreasing numbers of percent of aligned residues, here a snapshot of 20 out of a few hundreds with their corresponding PDB names.