1. The relative orientation observed for  helices packed on ß sheets

2. The Complementary twist model for the  helix to ß sheet packing

3. 1 2 3 4 Beta sheet structure Beta sheets have “topologies” that bring together distant portions of the sequence. Front: 1-2-5 Back: 7-6-3-4 2-1-4-3 1 3 4 2 5 6 7 Beta strands are numbered in sequence order.

4. The relative orientation of the packing ß sheet

5. Parallel beta sheets Concanavalin

6. ß-pleated sheet sandwich proteins

7. A model for the aligned packing of the ß sheet

8. The ß sheet to ß sheet packing in prealbumin

9. Orthogonal Beta Sheet Protein

10. A model for the orthogonal packing of the ß sheet

11. B-propeller from flu virus

12. B-barrel Porin (Channel) Protein

13. What accounts for the high stability of H  D- Crys? Hydrophobic domain cores Domain interface interactions

14. Hydrophobic domain interface residues N-terminal domainC-terminal domain Conservation among 35  -crystallin sequences: N-terminal Met43 Phe56 Ile81 C-terminal Leu145 Val132 Val170 Met43 -Met 77%Val 11.5%Ala 8.5%Ile 3% Phe56 -Phe 80%Val 8.5%Ile 8.5%Leu 3% Ile81 -Ile 80%Val 8.5%Leu 5.5%Pro 3%Thr 3% Val132 -Val 54.3%Ile 28.5%Leu 17.2% Leu145 -Leu 68.5%Tyr 20%Phe 11.5% Val170 -Val 49%Ile 42%Ala 3%Met 3%Leu 3%

15. Peripheral domain interface residues N-terminal domainC-terminal domain N-terminal Gln54 Arg79 C-terminal Gln143 Met147 Conservation among 35  -crystallin sequences: Gln54 -Gln 88.5%Met 8.5%Pro 3% Arg79 -Arg 83%Cys 8.5%Lys 5.5%His 3% Gln143 -Gln 80%Met 17%Leu 3% Met147 -Arg 85.5%Glu 8.5%Asp 3%Met 3%