FIGURE 5.

Subunit exchange between Rel species dramatically favors heterodimer formation. (a) The expected and observed population proportions are shown as a percentage of the aggregate populations. (b) Interface between the dimerisation domains of p50 (left, blue) and p65 (right, peach) in the structure of the p50/p65 heterodimer (PDB: 1VKX). The corresponding double‐stranded DNA oligo is omitted. Opposite faces of the dimerisation interface are shown from above (top) and from below (bottom). for the following: (c) p50/p65 (PDB ID: 1VKX), (d) p50/p50 (PDB ID: 1SVC), (e) p65/p65 (PDB ID: 2RAM). (f) Model of the apparent preference for the p50/p65 heterodimer, showing that (in the absence of further polypeptide modification or sequestration), the heterodimeric species should comprise the majority of cellular species after even modest diffusion away from sites of translation. p50 is represented in blue, and p65 is represented in peach