1Q2N

REFINED Solution NMR structure of the Z domain of STAPHYLOCOCCAL PROTEIN A

Summary for 1Q2N

• Entry DOI: 10.2210/pdb1q2n/pdb
• Related: 2SPZ
• NMR Information: BMRB: 4023
• Descriptor: IMMUNOGLOBULIN G BINDING PROTEIN A (1 entity in total)
• Functional Keywords: immunoglobulin-binding protein, three-helical bundle structure, residual dipolar couplings, immune system
• Biological source: Staphylococcus aureus
• Cellular location: Secreted, cell wall; Peptidoglycan-anchor (Potential): P38507
• Total number of polymer chains: 1
• Total formula weight: 6648.32

Authors

Zheng, D.,Tashiro, M.,Aramini, J.M.,Montelione, G.T. (deposition date: 2003-07-25, release date: 2003-08-12, Last modification date: 2024-05-22)

Primary citation

Zheng, D.,Aramini, J.M.,Montelione, G.T.
Validation of helical tilt angles in the solution NMR structure of the Z domain of Staphylococcal protein A by combined analysis of residual dipolar coupling and NOE data.
Protein Sci., 13:549-554, 2004

PubMed Abstract: Staphylococcal protein A (SpA) is a virulence factor from Staphylococcus aureus that is able to bind to immunoglobulins. The 3D structures of its immunoglobulin (Ig) binding domains have been extensively studied by NMR and X-ray crystallography, and are often used as model structures in developing de novo or ab initio strategies for predicting protein structure. These small three-helix-bundle structures, reported in free proteins or Ig-bound complexes, have been determined previously using medium- to high-resolution data. Although the location and relative orientation of the three helices in most of these published 3D domain structures are consistent, there are significant differences among the reported structures regarding the tilt angle of the first helix (helix 1). We have applied residual dipolar coupling data, together with nuclear Overhauser enhancement and scalar coupling data, in refining the NMR solution structure of an engineered IgG-binding domain (Z domain) of SpA. Our results demonstrate that the three helices are almost perfectly antiparallel in orientation, with the first helix tilting slightly away from the other two helices. We propose that this high-accuracy structure of the Z domain of SpA is a more suitable target for theoretical predictions of the free domain structure than previously published lower-accuracy structures of protein A domains.

PubMed: 14718654
DOI: 10.1110/ps.03351704

Experimental method

SOLUTION NMR