Figure 2
Some examples of protein domains with nontrivial entanglement, in which one notes a looped portion (red, with yellow ends, following the color code of Fig. 1d) intertwined with another portion of the protein, a thread (blue). (a) protein 2bjuA02, with L′ = 1.145 (also the blue chain contains a loop) and \({G^{\prime} }_{c}\) = 1.285 of similar magnitude; (b) protein 3thtA01, with significant entanglement (\({G^{\prime} }_{c}\) = −1.56) but without two linked loops (L′ = −0.34); (c) protein 3tnxA00, with large \({G^{\prime} }_{c}\) = −3.07, while L′ = −1.31 is much smaller and with the same sign; (d) protein 2i06A01, with \(L^{\prime} =0.74\simeq 1\), partitioned in the two corresponding linked loops and thus following the color code of Fig. 1c (green ends of the blue loop); (e) again 2i06A01, with \({G^{\prime} }_{c}\) = −1.26, highlighting the related loop-thread partition. In the last two points one notes that the sign of L′ is opposite to the sign of \({G^{\prime} }_{c}\). It is an example of the coexistence of different forms of entanglement in the same protein domain. (f) protein 1otjA00, one of the protein domains with largest (absolute) Gaussian Entanglement, with \({G^{\prime} }_{c}\) = −3.24 and L′ = −3.02. The red loop, with yellow ends, is extremely entangled with the blue portion (which in this case also contains a loop).
