1w09

Solution structure of the cis form of the human alpha-hemoglobin stabilizing protein (AHSP)

spinqualitylabelsall models 1w09 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1w09 is a 1 chain structure with sequence from Homo sapiens. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AHSP_HUMAN Acts as a chaperone to prevent the harmful aggregation of alpha-hemoglobin during normal erythroid cell development. Specifically protects free alpha-hemoglobin from precipitation. It is predicted to modulate pathological states of alpha-hemoglobin excess such as beta-thalassemia. Publication Abstract from PubMed 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. NMR structure of the alpha-hemoglobin stabilizing protein: insights into conformational heterogeneity and binding.,Santiveri CM, Perez-Canadillas JM, Vadivelu MK, Allen MD, Rutherford TJ, Watkins NA, Bycroft M J Biol Chem. 2004 Aug 13;279(33):34963-70. Epub 2004 Jun 3. PMID:15178680 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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