1QT1

CRYSTAL STRUCTURE OF XYLOSE ISOMERASE FROM STREPTOMYCES DIASTATICUS NO.7 M1033 AT 1.85 A RESOLUTION

Summary for 1QT1

• Entry DOI: 10.2210/pdb1qt1/pdb
• Descriptor: PROTEIN (XYLOSE ISOMERASE), COBALT (II) ION (3 entities in total)
• Functional Keywords: isomerase, xylose isomerase, glucose isomerase, streptomyces, true space group
• Biological source: Streptomyces diastaticus
• Cellular location: Cytoplasm: P50910
• Total number of polymer chains: 2
• Total formula weight: 85627.01

Authors

Niu, L.,Teng, M.,Zhu, X. (deposition date: 1999-06-29, release date: 2000-06-29, Last modification date: 2023-08-16)

Primary citation

Zhu, X.,Teng, M.,Niu, L.,Xu, C.,Wang, Y.
Structure of xylose isomerase from Streptomyces diastaticus no. 7 strain M1033 at 1.85 A resolution.
Acta Crystallogr.,Sect.D, 56:129-136, 2000

PubMed Abstract: The structure of xylose isomerase (XyI) from Streptomyces diastaticus No. 7 strain M1033 (SDXyI) has been refined at 1.85 A resolution to conventional and free R factors of 0.166 and 0.219, respectively. SDXyI was crystallized in space group P2(1)2(1)2, with unit-cell parameters a = 87.976, b = 98.836, c = 93.927 A. One dimer of the tetrametric molecule is found in each asymmetric unit. Each monomer consists of two domains: a large N-terminal domain (residues 1-320), containing a parallel eight-stranded alpha/beta barrel, and a small C-terminal loop (residues 321-387), containing five helices linked by random coil. The four monomers are essentially identical in the tetramer, possessing non-crystallographic 222 symmetry with one twofold axis essentially coincident with the crystallographic twofold axis in the space group P2(1)2(1)2, which may explain why the diffraction pattern has strong pseudo-I222 symmetry even at medium resolution. The crystal structures of XyIs from different bacterial strains, especially from Streptomyces, are similar. The alpha2 helix of the alpha/beta barrel has a different position in the structures of different XyIs. The conformation of C-terminal fragment 357-364 in the SDXyI structure has a small number of differences to that of other XyIs. Two Co(2+) ions rather than Mg(2+) ions exist in the active site of the SDXyI structure; SDXyI seems to prefer to bind Co(2+) ions rather than Mg(2+) ions.

PubMed: 10666592
DOI: 10.1107/S0907444999015097

Experimental method

X-RAY DIFFRACTION (1.85 Å)