Fig. 2
From: A five-residue motif for the design of domain swapping in proteins
QVVAG segment from stefin B drives domain swapping in L1MN. a Far-UV CD spectra of wt MNEI and L1MN are shown. b Size exclusion profiles of wt MNEI and L1MN, at pH 7, are shown. The profile of the calibration mix (marker) is shown in gray. c Plot of the logarithm of molecular weight vs. elution volume generated using the elution profile of the calibration mix in (b) is shown. The data were fitted to a straight line (r = 0.99), and the apparent molecular weights of wt MNEI (■ ~10 kDa) and L1MN (● ~20 kDa) were determined. d Structure of the L1MN domain-swapped dimer is shown. Two polypeptide chains contributing to the swapped dimer (protomers) are shown in orange and purple. The N-termini and C-termini, and different loops of both the polypeptide chains contributing to the swapped dimer are indicated, except for loop3 of protomer 2, which is not clearly visible in the orientation depicted. e A space-filling model of the L1MN domain-swapped dimer is shown to highlight the quaternary arrangement of the protomers. f Zoomed in view of the hinge loop from d, showing the QVVAG stretch within the electron density map. The 2Fo-Fc simulated anneal composite omit map is shown at a contour level of 1.6σ. Side chain nitrogen atoms are colored blue, and oxygen atoms are colored red. All other side chain atoms are colored yellow. g The backbone trace of the hinge region is shown, and the backbone hydrogen bonds formed in the hinge region are shown by green lines. Source data are provided as a Source Data file
