1w0a: Difference between revisions

[[Image:1w0a.gif|left|200px]]<br /><applet load="1w0a" size="350" color="white" frame="true" align="right" spinBox="true"  

The structure of alpha-hemoglobin stabilizing protein (AHSP), a molecular chaperone for free alpha-hemoglobin, has been determined using NMR spectroscopy. The protein native state shows conformational heterogeneity attributable to the isomerization of the peptide bond preceding a conserved proline residue. The two equally populated cis and trans forms both adopt an elongated antiparallel three alpha-helix bundle fold but display major differences in the loop between the first two helices and at the C terminus of helix 3. Proline to alanine single point mutation of the residue Pro-30 prevents the cis/trans isomerization. The structure of the P30A mutant is similar to the structure of the trans form of AHSP in the loop 1 region. Both the wild-type AHSP and the P30A mutant bind to alpha-hemoglobin, and the wild-type conformational heterogeneity is quenched upon complex formation, suggesting that just one conformation is the active form. Changes in chemical shift observed upon complex formation identify a binding interface comprising the C terminus of helix 1, the loop 1, and the N terminus of helix 2, with the exposed residues Phe-47 and Tyr-51 being attractive targets for molecular recognition. The characteristics of this interface suggest that AHSP binds at the intradimer alpha1beta1 interface in tetrameric HbA.

1W0A is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1W0A OCA].  

[[Category: Allen, M D.]]

[[Category: Perez-Canadillas, J M.]]

[[Category: Rutherford, T J.]]

[[Category: Santiveri, C M.]]

[[Category: Vadivelu, M K.]]

[[Category: Watkins, N A.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:39:08 2008''