Download MendeleyCrystal structure of AlgQ2, a macromolecule (alginate)-binding protein of Sphingomonas sp. A1 at 2.0A resolution.
Momma, K., Mikami, B., Mishima, Y., Hashimoto, W., Murata, K.(2002) J Mol Biol 316: 1051-1059
- PubMed: 11884143
- DOI: https://doi.org/10.1006/jmbi.2001.5393
- Primary Citation of Related Structures:
1KWH - PubMed Abstract:
Sphingomonas sp. A1 possesses a high molecular mass (average 25,700 Da) alginate uptake system mediated by a novel pit-dependent ABC transporter. The X-ray crystallographic structure of AlgQ2 (57,200 Da), an alginate-binding protein in the system, was determined by the multiple isomorphous replacement method and refined at 2.0 A resolution with a final R-factor of 18.3% for 15 to 2.0 A resolution data. The refined structure of AlgQ2 was comprised of 492 amino acid residues, 172 water molecules, and one calcium ion. AlgQ2 was composed of two globular domains with a deep cleft between them, which is expected to be the alginate-binding site. The overall structure is basically similar to that of maltose/maltodextrin-binding protein, except for the presence of an N2-subdomain. The entire calcium ion-binding site is similar to the site in the EF-hand motif, but comprises a ten residue loop. This calcium ion-binding site is about 40 A away from the alginate-binding site.
Organizational Affiliation:
Department of Basic and Applied Molecular Biotechnology, Division of Food and Biological Science, Graduate School of Agriculture, Kyoto University, Uji, 611-0011, Japan.
