1w0a

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

Structural highlights

1w0a 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.[1]

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[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

  1. Kihm AJ, Kong Y, Hong W, Russell JE, Rouda S, Adachi K, Simon MC, Blobel GA, Weiss MJ. An abundant erythroid protein that stabilizes free alpha-haemoglobin. Nature. 2002 Jun 13;417(6890):758-63. PMID:12066189 doi:http://dx.doi.org/10.1038/nature00803
  2. Santiveri CM, Perez-Canadillas JM, Vadivelu MK, Allen MD, Rutherford TJ, Watkins NA, Bycroft M. NMR structure of the alpha-hemoglobin stabilizing protein: insights into conformational heterogeneity and binding. J Biol Chem. 2004 Aug 13;279(33):34963-70. Epub 2004 Jun 3. PMID:15178680 doi:10.1074/jbc.M405016200
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