Crystallographic structure and functional interpretation of the cytoplasmic domain of erythrocyte membrane band 3.
The red blood cell membrane (RBCM) is a primary model for animal cell plasma membranes. One of its major organizing centers is the cytoplasmic domain of band 3 (cdb3), which links multiple proteins to the membrane. Included among its peripheral protein ligands are ankyrin (the major bridge to the spectrin-actin skeleton), protein 4. 1, protein 4.2, aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphofructokinase, deoxyhemoglobin, p72syk protein tyrosine kinase, and hemichromes. The crystal structure of cdb3 is reported at 0.26 nm (2.6 A) resolution. A tight symmetric dimer is formed by cdb3; it is stabilized by interlocked dimerization arms contributed by both monomers. Each subunit also includes a larger peripheral protein binding domain with an alpha(+) beta-fold. The binding sites of several peripheral proteins are localized in the structure, and the nature of the major conformational change that regulates membrane-skeletal interactions is evaluated. An improved structural definition of the protein network at the inner surface of the RBCM is now possible.
Zhang
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Departments of Chemistry and Biological Sciences, Purdue University, West Lafayette, IN 47907-1392, USA.
Kiyatkin
A
A
Bolin
J T
JT
Low
P S
PS
D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry*; D017487:Ankyrins / Q000737:chemistry; D018360:Crystallography, X-Ray; D019281:Dimerization; D004910:Erythrocyte Membrane / Q000737:chemistry; D006801:Humans; D008565:Membrane Proteins / Q000097:blood / Q000737:chemistry; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry; D017433:Protein Structure, Secondary; D021122:Protein Subunits
D001457:Anion Exchange Protein 1, Erythrocyte; D017487:Ankyrins; D008565:Membrane Proteins; D010446:Peptide Fragments; D021122:Protein Subunits