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1bz0
From Proteopedia
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HEMOGLOBIN A (HUMAN, DEOXY, HIGH SALT)
Overview
Hemoglobin Catonsville is a mutation of human hemoglobin (an alpha 2 beta, 2 tetramer) in which a glutamate residue is inserted into the first turn, of a highly conserved 3(10) helix (the C helix) of each alpha subunit. In, theory, amino acid insertions (or deletions) in protein helices can be, accommodated via two distinct mechanisms. One, termed the register shift, mechanism, preserves the geometry of the helix while requiring all of the, residues on one flank of the insertion site to rotate by 100 degrees in, the case of an alpha helix or by 120 degrees in the case of a 3(10) helix., The other, termed the bulge (or indentation) mechanism, distorts the local, geometry of the helix but does not alter the helix register., High-resolution X-ray diffraction analysis of deoxyhemoglobin Catonsville, shows that the inserted residue is accommodated as a bulge, demonstrating, that this is a viable mechanism. (In contrast, no such evidence is yet, available for the register shift mechanism.) More specifically, the, insertion converts one turn of the C helix from 3(10) geometry to alpha, helix-like geometry, raising the possibility that a common mechanism for, accommodating insertions and deletions within helices may involve, localized interconversions between 3(10), alpha, and pi helical, structures.
About this Structure
1BZ0 is a Protein complex structure of sequences from Homo sapiens with HEM as ligand. Full crystallographic information is available from OCA.
Reference
Accommodation of insertions in helices: the mutation in hemoglobin Catonsville (Pro 37 alpha-Glu-Thr 38 alpha) generates a 3(10)-->alpha bulge., Kavanaugh JS, Moo-Penn WF, Arnone A, Biochemistry. 1993 Mar 16;32(10):2509-13. PMID:8448109
Page seeded by OCA on Thu Nov 8 12:57:59 2007
