1XLM

D254E, D256E MUTANT OF D-XYLOSE ISOMERASE COMPLEXED WITH AL3 AND XYLITOL

Summary for 1XLM

• Entry DOI: 10.2210/pdb1xlm/pdb
• Descriptor: D-XYLOSE ISOMERASE, Xylitol, ALUMINUM ION, ... (4 entities in total)
• Functional Keywords: isomerase, al, substrate induced metal ion movement, xylose metabolism, pentose shunt
• Biological source: Arthrobacter sp. NRRL
• Cellular location: Cytoplasm: P12070
• Total number of polymer chains: 2
• Total formula weight: 86886.66

Authors

Gerczei, T.,Bocskei, Z.S.,Szabo, E.,Naray-Szabo, G.,Asboth, B. (deposition date: 1997-07-22, release date: 1998-01-28, Last modification date: 2024-05-22)

Primary citation

Gerczei, T.,Bocskei, Z.,Szabo, E.,Asboth, B.,Naray-Szabo, G.
Structure determination and refinement of the Al3+ complex of the D254,256E mutant of Arthrobacter D-xylose isomerase at 2.40 A resolution. Further evidence for inhibitor-induced metal ion movement.
Int.J.Biol.Macromol., 25:329-336, 1999

PubMed Abstract: The structure of the D254.256E double mutant of Arthrobacter xylose isomerase with Al3+ at both metal-binding sites was determined by the molecular replacement method at a conventional R-factor of 0.179. Binding of the two Al3+ does not alter the overall structure significantly. However, there are local rearrangements in the octahedral co-ordination sphere of the Al3+. The inhibitor molecule moves somewhat away from the active site. Furthermore, evidence was revealed for metal ion movement from site 2(1) to site 2(2) upon double mutation. Xylose isomerase requires two divalent metal cations for activation. The catalytic metal ion is translocated 1.8 A away from its initial position during the catalytic reaction. The fact that both activating and inactivating metals (including Al3+) were found exclusively at a single location in the double mutant was an indication that the consequently missing shuttle may account for the crippled catalytic efficiency.

PubMed: 10456773
DOI: 10.1016/S0141-8130(99)00051-3

Experimental method

X-RAY DIFFRACTION (2.4 Å)