1ps2
From Proteopedia
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HIGH RESOLUTION NMR SOLUTION STRUCTURE OF HUMAN PS2, 19 STRUCTURES
Overview
pNR-2/pS2 is a 60 residue extracellular protein, which was originally, discovered in human breast cancer cells, and subsequently found in other, tumours and normal gastric epithelial cells. We have determined the, three-dimensional solution structure of a C58S mutant of human pNR-2/pS2, using 639 distance and 137 torsion angle constraints obtained from, analysis of multidimensional NMR spectra. A series of simulated annealing, calculations resulted in the unambiguous determination of the protein's, disulphide bonding pattern and produced a family of 19 structures, consistent with the constraints. The peptide contains a single "trefoil", sequence motif, a region of about 40 residues with a characteristic, sequence pattern, which has been found, either singly or as a repeat, in, about a dozen extracellular proteins. The trefoil domain contains three, disulphide bonds, whose 1-5, 2-4 and 3-6 cysteine pairings form the, structure into three closely packed loops with only a small amount of, secondary structure, which consists of a short alpha-helix packed against, a two-stranded antiparallel beta-sheet. The structure of the domain is, very similar to those of the two trefoil domains that occur in porcine, spasmolytic polypeptide (PSP), the only member of the trefoil family whose, three-dimensional structure has been previously determined. Outside the, trefoil domain, which forms the compact "head" of the molecule, the N and, C-terminal strands are closely associated, forming an extended "tail", which has some beta-sheet character for part of its length and which, becomes more disordered towards the termini as indicated by (15)N{(1)H}, NOEs. We have considered the structural implications of the possible, formation of a native C58-C58 disulphide-bonded homodimer. Comparison of, the surface features of pNR-2/pS2 and PSP, and consideration of the, sequences of the other human trefoil domains in the light of these, structures, illuminates the possible role of specific residues in, ligand/receptor binding.
About this Structure
1PS2 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
High-resolution solution structure of human pNR-2/pS2: a single trefoil motif protein., Polshakov VI, Williams MA, Gargaro AR, Frenkiel TA, Westley BR, Chadwick MP, May FE, Feeney J, J Mol Biol. 1997 Mar 28;267(2):418-32. PMID:9096235
Page seeded by OCA on Mon Nov 12 18:46:37 2007
