1KWH

Structure Analysis AlgQ2, a Macromolecule(alginate)-Binding Periplasmic Protein of Sphingomonas sp. A1.

Summary for 1KWH

• Entry DOI: 10.2210/pdb1kwh/pdb
• Descriptor: Macromolecule-Binding Periplasmic Protein, CALCIUM ION (3 entities in total)
• Functional Keywords: binding protein, alginate, protein binding
• Biological source: Sphingomonas sp.
• Total number of polymer chains: 1
• Total formula weight: 57291.79

Authors

Momma, K.,Mikami, B.,Mishima, Y.,Hashimoto, W.,Murata, K. (deposition date: 2002-01-29, release date: 2002-02-13, Last modification date: 2024-03-13)

Primary citation

Momma, K.,Mikami, B.,Mishima, Y.,Hashimoto, W.,Murata, K.
Crystal structure of AlgQ2, a macromolecule (alginate)-binding protein of Sphingomonas sp. A1 at 2.0A resolution.
J.Mol.Biol., 316:1051-1059, 2002

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.

PubMed: 11884143
DOI: 10.1006/jmbi.2001.5393

Experimental method

X-RAY DIFFRACTION (2 Å)