Abstract
The primary metabolic route for d-xylose, the second most abundant sugar in nature, is via the pentose phosphate pathway after a two-step or three-step conversion to xylulose-5-phosphate. Xylulose kinase (XK; EC 2.7.1.17) phosphorylates d-xylulose, the last step in this conversion. The apo and d-xylulose-bound crystal structures of Escherichia coli XK have been determined and show a dimer composed of two domains separated by an open cleft. XK dimerization was observed directly by a cryo-EM reconstruction at 36 Å resolution. Kinetic studies reveal that XK has a weak substrate-independent MgATP-hydrolyzing activity, and phosphorylates several sugars and polyols with low catalytic efficiency. Binding of pentulose and MgATP to form the reactive ternary complex is strongly synergistic. Although the steady-state kinetic mechanism of XK is formally random, a path is preferred in which d-xylulose binds before MgATP. Modelling of MgATP binding to XK and the accompanying conformational change suggests that sugar binding is accompanied by a dramatic hinge-bending movement that enhances interactions with MgATP, explaining the observed synergism. A catalytic mechanism is proposed and supported by relevant site-directed mutants.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 783-798 |
| Number of pages | 16 |
| Journal | Journal of Molecular Biology |
| Volume | 365 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 19 2007 |
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Keywords
- ATPase
- FGGY kinase
- mechanism
- X-ray structure
- xylulokinase
ASJC Scopus subject areas
- Virology
Cite this
Structural and Kinetic Studies of Induced Fit in Xylulose Kinase from Escherichia coli. / Di Luccio, Eric; Petschacher, Barbara; Voegtli, Jennifer; Chou, Hui Ting; Stahlberg, Henning; Nidetzky, Bernd; Wilson, David K.
In: Journal of Molecular Biology, Vol. 365, No. 3, 19.01.2007, p. 783-798.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Structural and Kinetic Studies of Induced Fit in Xylulose Kinase from Escherichia coli
AU - Di Luccio, Eric
AU - Petschacher, Barbara
AU - Voegtli, Jennifer
AU - Chou, Hui Ting
AU - Stahlberg, Henning
AU - Nidetzky, Bernd
AU - Wilson, David K.
PY - 2007/1/19
Y1 - 2007/1/19
N2 - The primary metabolic route for d-xylose, the second most abundant sugar in nature, is via the pentose phosphate pathway after a two-step or three-step conversion to xylulose-5-phosphate. Xylulose kinase (XK; EC 2.7.1.17) phosphorylates d-xylulose, the last step in this conversion. The apo and d-xylulose-bound crystal structures of Escherichia coli XK have been determined and show a dimer composed of two domains separated by an open cleft. XK dimerization was observed directly by a cryo-EM reconstruction at 36 Å resolution. Kinetic studies reveal that XK has a weak substrate-independent MgATP-hydrolyzing activity, and phosphorylates several sugars and polyols with low catalytic efficiency. Binding of pentulose and MgATP to form the reactive ternary complex is strongly synergistic. Although the steady-state kinetic mechanism of XK is formally random, a path is preferred in which d-xylulose binds before MgATP. Modelling of MgATP binding to XK and the accompanying conformational change suggests that sugar binding is accompanied by a dramatic hinge-bending movement that enhances interactions with MgATP, explaining the observed synergism. A catalytic mechanism is proposed and supported by relevant site-directed mutants.
AB - The primary metabolic route for d-xylose, the second most abundant sugar in nature, is via the pentose phosphate pathway after a two-step or three-step conversion to xylulose-5-phosphate. Xylulose kinase (XK; EC 2.7.1.17) phosphorylates d-xylulose, the last step in this conversion. The apo and d-xylulose-bound crystal structures of Escherichia coli XK have been determined and show a dimer composed of two domains separated by an open cleft. XK dimerization was observed directly by a cryo-EM reconstruction at 36 Å resolution. Kinetic studies reveal that XK has a weak substrate-independent MgATP-hydrolyzing activity, and phosphorylates several sugars and polyols with low catalytic efficiency. Binding of pentulose and MgATP to form the reactive ternary complex is strongly synergistic. Although the steady-state kinetic mechanism of XK is formally random, a path is preferred in which d-xylulose binds before MgATP. Modelling of MgATP binding to XK and the accompanying conformational change suggests that sugar binding is accompanied by a dramatic hinge-bending movement that enhances interactions with MgATP, explaining the observed synergism. A catalytic mechanism is proposed and supported by relevant site-directed mutants.
KW - ATPase
KW - FGGY kinase
KW - mechanism
KW - X-ray structure
KW - xylulokinase
UR - http://www.scopus.com/inward/record.url?scp=33845799646&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33845799646&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2006.10.068
DO - 10.1016/j.jmb.2006.10.068
M3 - Article
C2 - 17123542
AN - SCOPUS:33845799646
VL - 365
SP - 783
EP - 798
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 3
ER -