1L5C

Solution Structure of the Monomeric Form of a Mutant Unliganded Bovine Neurophysin, 20 Structures

Summary for 1L5C

• Entry DOI: 10.2210/pdb1l5c/pdb
• Related: 1L5D 1NPO 2BN2
• Descriptor: NEUROPHYSIN 1 (1 entity in total)
• Functional Keywords: nmr analysis neurophysin monomer, hormone-growth factor complex, hormone/growth factor
• Biological source: Bos taurus (cattle)
• Cellular location: Secreted: P01175
• Total number of polymer chains: 1
• Total formula weight: 9286.44

Authors

Nguyen, T.L.,Breslow, E. (deposition date: 2002-03-06, release date: 2002-03-20, Last modification date: 2024-11-13)

Primary citation

Nguyen, T.L.,Breslow, E.
NMR analysis of the monomeric form of a mutant unliganded bovine neurophysin: comparison with the crystal structure of a neurophysin dimer.
Biochemistry, 41:5920-5930, 2002

PubMed Abstract: Determination of the structure of the unliganded monomeric state of neurophysin is central to an understanding of the allosteric relationship between neurophysin peptide-binding and dimerization. We examined this state by NMR, using the weakly dimerizing H80E mutant of bovine neurophysin-I. The derived structure, to which more than one conformer appeared to contribute, was compared with the crystal structure of the unliganded des 1-6 bovine neurophysin-II dimer. Significant conformational differences between the two proteins were evident in the orientation of the 3,10 helix, in the 50-58 loop, in beta-turns, and in specific intrachain contacts between amino- and carboxyl domains. However, both had similar secondary structures, in independent confirmation of earlier circular dichroism studies. Previously suggested interactions between the amino terminus and the 50-58 loop in the monomer were also confirmed. Comparison of the observed differences between the two proteins with demonstrated effects of dimerization on the NMR spectrum of bovine neurophysin-I, and preliminary investigation of the effects of dimerization on H80E spectra, allowed tentative distinction between the contributions of sequence and self-association differences to the difference in conformation. Regions altered by dimerization encompass most binding site residues, providing a potential explanation of differences in binding affinity between the unliganded monomeric and dimeric states. Differences between monomer and dimer states in turns, interdomain contacts, and within the interdomain segment of the 50-58 loop suggest that the effects of dimerization on intrasubunit conformation reflect the need to adjust the relative positions of the interface segments of the two domains for optimal interaction with the adjacent subunit and/or reflect the dual role of some residues as participants both at the interface and in interdomain contacts.

PubMed: 11980496
DOI: 10.1021/bi012067k

Experimental method

SOLUTION NMR