Prediction of the structure of filaminΔ5. Structural prediction of a region of filaminΔ5 corresponding to segments 4 through 6 of the full length filamin (amino acids 547 to 838, including the first two β strands of segment 5) but with residues 672 through 743 (most of segment 5) deleted (DDB0201554). The prediction was made using the SwissModel first approach method accessed through the ExPASy Proteomics Server [20-25]. The resulting prediction was based on known D. discoideum and human filamin structures. The structures for repeat segments 4–6 have been determined by Popowitcz et al.  and as the repeats are very similar it is believed that repeat segments 1–3 would contain a similar structure to repeats 4 and 5. Therefore this figure uses the deletion of repeat segment 5 as an example which could be extrapolated for all the other repeat segments. The top panel is the known structure  of repeat segments 4 through to 6, the bottom panel shows the predicted structure for the corresponding region of filaminΔ5. This figure illustrates that by deleting all but the first two β strands of a repeat segment, it is possible to correctly fold and maintain the correct distance between the repeat segments that flank the deleted region. The gold arrows indicate the position of the sequences corresponding to the first two β strands of segment 5 in the wild type filamin structure.
Annesley et al. BMC Cell Biology 2007 8:48 doi:10.1186/1471-2121-8-48