3air

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Crystal structure of beta-glucosidase in wheat complexed with 2-deoxy-2-fluoroglucoside and dinitrophenolCrystal structure of beta-glucosidase in wheat complexed with 2-deoxy-2-fluoroglucoside and dinitrophenol

Structural highlights

3air is a 1 chain structure with sequence from Triticum aestivum. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2Å
Ligands:,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

HGL1B_WHEAT Acts in defense of young plant parts against pests via the production of hydroxamic acids from hydroxamic acid glucosides. Enzymatic activity is highly correlated with plant growth. The preferred substrate is DIMBOA-beta-D-glucoside.[1] [2]

Publication Abstract from PubMed

The beta-D-glucosidases from wheat (Triticum aestivum) and rye (Secale cereale) hydrolyze benzoxazinone-glucose conjugates. Although wheat and rye glucosidases have high sequence identity, they have different substrate preferences; the wheat enzyme favors DIMBOA-Glc (2-O-beta-D-glucopyranosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one) over DIBOA-Glc (7-demethoxy-DIMBOA-Glc), whereas the rye enzyme preference is the opposite. To investigate the mechanism of substrate binding, we analyzed crystal structures of an inactive mutant of the wheat glucosidase complexed with the natural substrate DIMBOA-Glc, wheat and rye glucosidases complexed with an aglycone DIMBOA, and wheat and rye glucosidases complexed with an inhibitor 2-fluoro-2-deoxy-beta-D-glucose. The binding position of substrate in the active site was determined but interaction between the substrate and Ser-464 or Leu-465 was not observed, although amino acid residues at these two positions are the only structural distinctions between wheat and rye glucosidase catalytic pockets. Variation at these two positions alters the width of the pocket entrance, which may relate to observed differences in substrate specificity. The side chain of Glu-462 that forms hydrogen bonds with the glucose moiety of DIMBOA-Glc moved deeper into the pocket upon substrate binding, and mutation of this residue dramatically decreased enzyme activity.

Active-site architecture of benzoxazinone-glucoside beta-D-glucosidases in Triticeae.,Sue M, Nakamura C, Miyamoto T, Yajima S Plant Sci. 2011 Feb;180(2):268-75. Epub 2010 Sep 19. PMID:21421370[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Sue M, Ishihara A, Iwamura H. Purification and characterization of a hydroxamic acid glucoside beta-glucosidase from wheat (Triticum aestivum L.) seedlings. Planta. 2000 Feb;210(3):432-8. PMID:10750901
  2. Sue M, Yamazaki K, Yajima S, Nomura T, Matsukawa T, Iwamura H, Miyamoto T. Molecular and structural characterization of hexameric beta-D-glucosidases in wheat and rye. Plant Physiol. 2006 Aug;141(4):1237-47. Epub 2006 Jun 2. PMID:16751439 doi:10.1104/pp.106.077693
  3. Sue M, Nakamura C, Miyamoto T, Yajima S. Active-site architecture of benzoxazinone-glucoside beta-D-glucosidases in Triticeae. Plant Sci. 2011 Feb;180(2):268-75. Epub 2010 Sep 19. PMID:21421370 doi:10.1016/j.plantsci.2010.09.001

3air, resolution 2.00Å

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