The relative orientation observed for helices packed on ß sheets

The Complementary twist model for the helix to ß sheet packing

12

3

4

Beta sheet structure

Beta sheets have “topologies” that bring together distant portions of the sequence.

Front: 1-2-5Back: 7-6-3-4

2-1-4-3

1

34

25

67

Beta strands are numbered in sequence order.

The relative orientation of the packing ß sheet

Parallel beta sheetsConcanavalin

ß-pleated sheet sandwich proteins

A model for the aligned packing of the ß sheet

The ß sheet to ß sheet packing in prealbumin

Orthogonal Beta Sheet Protein

A model for the orthogonal packing of the ß sheet

B-propeller from flu virus

B-barrel Porin (Channel) Protein

What accounts for the high stability of HD-Crys?

Hydrophobic domain cores

Domain interface interactions

Hydrophobic domain interface residues

N-terminal domain C-terminal domain

Conservation among 35 -crystallin sequences:

N-terminal

Met43Phe56Ile81

C-terminal

Leu145Val132Val170

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%

Peripheral domain interface residues

N-terminal domain C-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%