chapter 3 alpha-domain structures -...
TRANSCRIPT
Chapter 3 Alpha-domain structures
Coiled-coil Helical bundle
Globin fold
COILED-COIL STRUCTURES
Examples: mammals' hair (including wool), hooves, nails, rhinoceros horns, much of the outer layer of skin
α-Keratin: a Coiled Coil
Coiled-coil α helices contain a repetitive heptad amino acid sequence pattern
Salt bridges can stabilize coiled-coil structure
Packing side chains in the hydrophobic core of coiled-coil structure: “knobs in
holes” model
Coiled Coils in The Nature: Protein Binding
[Marsden and Kros (2010) Angew. Chem. Int. Ed.]
Coiled Coils in The Nature: Structural Functions
[Marsden and Kros (2010) Angew. Chem. Int. Ed.]
NuMa (Nuclear Mitotic Apparatus): a fibrous nucleoskeletal protein
Coiled Coils in The Nature: Dynamic Functions
[Marsden and Kros (2010) Angew. Chem. Int. Ed.]
HELIX BUNDLE STRUCTURES
The four-helix bundle is a common domain structure in α proteins
Alpha-helical domains are sometimes large and complex
Bulgecin, a glycopeptide inhibitor
70-kDa soluble lytic transglycosylase (SLT70), a target for bulgecin
GLOBIN FOLD
The globin fold is present in myoglobin and hemoglobin
The globin fold has been preserved during evolution
Ridges of one α helix fit into grooves of an adjacent helix
ridge
groove
The “ridges in grooves” model
Globin fold
Four-helix bundle
Sickle-cell hemoglobin confers resistance to malaria: E6V mutation