1mmc: Difference between revisions

[[Image:1mmc.gif|left|200px]]<br /><applet load="1mmc" size="350" color="white" frame="true" align="right" spinBox="true"  

The conformation in water of antimicrobial protein 2 from Amaranthus caudatus (Ac-AMP2) was determined using 1H NMR, DIANA and restrained molecular modeling. Ac-AMP2 is a 30 amino acid residue, lectin-like protein that specifically binds to chitin, a polymer of beta-1,4-N-acetyl-D-glucosamine. After sequence specific resonance assignments, a total of 198 distance restraints were collected from 2D NOESY buildup spectra at 500 MHz at pH 2, supplemented by a 2D NOESY spectrum at 600 MHz. The location of the three previously unassigned disulfide bridges was determined from preliminary DIANA structures, using a statistical analysis of intercystinyl distances. The solution structure of Ac-AMP2 is presented as a set of 26 DIANA structures, further refined by restrained molecular dynamics using a simulated annealing protocol in the AMBER force field, with a backbone r.m.s.d. for the well defined Glu3-Cys28 segment of 0.69(+/-0.12) angstroms. The main structural element is an antiparallel beta-sheet from Met13 to Lys23 including a betaI-turn over Gln17-Phel8 with a beta bulge at Gly19. In addition, a beta'I turn over Arg6-Gly7, a beta'III turn over Ser11-Gly12 and a helical turn from Gly24 to Cys28 are identified. This structure is very similar to the equivalent regions of the X-ray structure of wheat germ agglutinin and the NMR structure of hevein.

1MMC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Amaranthus_caudatus Amaranthus caudatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MMC OCA].  

[[Category: Martins, J C.]]

[[Category: Pepermans, H A.M.]]

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