TY - JOUR
T1 - The dual nature of the wheat xylanase protein inhibitor XIP-I
T2 - Structural basis for the inhibition of family 10 and family 11 xylanases
AU - Payan, Françoise
AU - Leone, Philippe
AU - Porciero, Sophie
AU - Furniss, Caroline
AU - Tahir, Tariq
AU - Williamson, Gary
AU - Durand, Anne
AU - Manzanares, Paloma
AU - Gilbert, Harry J.
AU - Juge, Nathalie
AU - Roussel, Alain
PY - 2004/8/20
Y1 - 2004/8/20
N2 - The xylanase inhibitor protein I (XIP-I) from wheat Triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). The crystal structures of XIP-I in complex with Aspergillus nidulans (GH10) and Penicillium funiculosum (GH11) xylanases have been solved at 1.7 and 2.5 Å resolution, respectively. The inhibition strategy is novel because XIP-I possesses two independent enzyme-binding sites, allowing binding to two glycoside hydrolases that display a different fold. Inhibition of the GH11 xylanase is mediated by the insertion of an XIP-I ∏-shaped loop (Lα4β5) into the enzyme active site, whereas residues in the helix α7 of XIP-I, pointing into the four central active site subsites, are mainly responsible for the reversible inactivation of GH10 xylanases. The XIP-I strategy for inhibition of xylanases involves substrate-mimetic contacts and interactions occluding the active site. The structural determinants of XIP-I specificity demonstrate that the inhibitor is able to interact with GH10 and GH11 xylanases of both fungal and bacterial origin. The biological role of the xylanase inhibitors is discussed in light of the present structural data.
AB - The xylanase inhibitor protein I (XIP-I) from wheat Triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). The crystal structures of XIP-I in complex with Aspergillus nidulans (GH10) and Penicillium funiculosum (GH11) xylanases have been solved at 1.7 and 2.5 Å resolution, respectively. The inhibition strategy is novel because XIP-I possesses two independent enzyme-binding sites, allowing binding to two glycoside hydrolases that display a different fold. Inhibition of the GH11 xylanase is mediated by the insertion of an XIP-I ∏-shaped loop (Lα4β5) into the enzyme active site, whereas residues in the helix α7 of XIP-I, pointing into the four central active site subsites, are mainly responsible for the reversible inactivation of GH10 xylanases. The XIP-I strategy for inhibition of xylanases involves substrate-mimetic contacts and interactions occluding the active site. The structural determinants of XIP-I specificity demonstrate that the inhibitor is able to interact with GH10 and GH11 xylanases of both fungal and bacterial origin. The biological role of the xylanase inhibitors is discussed in light of the present structural data.
UR - http://www.scopus.com/inward/record.url?scp=4143103785&partnerID=8YFLogxK
U2 - 10.1074/jbc.M404225200
DO - 10.1074/jbc.M404225200
M3 - Article
C2 - 15181003
AN - SCOPUS:4143103785
SN - 0021-9258
VL - 279
SP - 36029
EP - 36037
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 34
ER -