1T6G: Crystal Structure Of The Triticum Aestivum Xylanase Inhibitor-i In Complex With Aspergillus Niger Xylanase-i

Plants developed a diverse battery of defense mechanisms in response to continual challenges by a broad spectrum of pathogenic microorganisms. Their defense arsenal includes inhibitors of cell wall-degrading enzymes, which hinder a possible invasion and colonization by antagonists. The structure of Triticum aestivum xylanase inhibitor-I (TAXI-I), a first member of potent TAXI-type inhibitors of fungal and bacterial family 11 xylanases, has been determined to 1.7-A resolution. Surprisingly, TAXI-I displays structural homology with the pepsin-like family of aspartic proteases but is proteolytically nonfunctional, because one or more residues of the essential catalytical triad are absent. The structure of the TAXI-I. Aspergillus niger xylanase I complex, at a resolution of 1.8 A, illustrates the ability of tight binding and inhibition with subnanomolar affinity and indicates the importance of the C-terminal end for the differences in xylanase specificity among different TAXI-type inhibitors.
PDB ID: 1T6GDownload
MMDB ID: 33505
PDB Deposition Date: 2004/5/6
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 1.8  Å
Source Organism:
Aspergillus niger
Similar Structures:
Biological Unit for 1T6G: dimeric; determined by author and by software (PISA)
Molecular Components in 1T6G
Label Count Molecule
Proteins (2 molecules)
Xylanase Inhibitor
Molecule annotation
Endo-1,4-beta-xylanase I
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB