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The complete triphosphate moiety of non-hydrolyzable substrate analogues is required for a conformational shift of the flexible C-terminus in E. coli dUTP pyrophosphatase

Vertessy, Beata G. ; Larsson, Gunilla ; Persson, Tina ; Bergman, Anna-Carin ; Persson, Rebecca and Nyman, Per-Olof LU (1998) In FEBS Letters 421(1). p.83-88
Abstract
The molecular mechanism of substrate analogue interaction with Escherichia coli dUTPase was investigated, using the non-hydrolyzable 2'-deoxyuridine 5'-(α,β-imido)triphosphate (α,β-imido-dUTP). Binding of this analogue induces a difference in the far UV circular dichroism (CD) spectrum arguing for a significant change in protein conformation. The spectral shift is strictly Mg2+-dependent, does not appear with dUDP instead of α,β-imido-dUTP and is not elicited if the flexible C-terminal arm is deleted from the protein by limited tryptic digestion. Involvement of the C-terminal arm in α,β-imido-dUTP binding is consistent with the finding that this analogue protects against tryptic hydrolysis at Arg-141. Near UV CD of ligand-enzyme complexes... (More)
The molecular mechanism of substrate analogue interaction with Escherichia coli dUTPase was investigated, using the non-hydrolyzable 2'-deoxyuridine 5'-(α,β-imido)triphosphate (α,β-imido-dUTP). Binding of this analogue induces a difference in the far UV circular dichroism (CD) spectrum arguing for a significant change in protein conformation. The spectral shift is strictly Mg2+-dependent, does not appear with dUDP instead of α,β-imido-dUTP and is not elicited if the flexible C-terminal arm is deleted from the protein by limited tryptic digestion. Involvement of the C-terminal arm in α,β-imido-dUTP binding is consistent with the finding that this analogue protects against tryptic hydrolysis at Arg-141. Near UV CD of ligand-enzyme complexes reveals a characteristic difference in the microenvironments of enzyme-bound dUDP and α,β-imido-dUTP, a difference not observable in C-terminally truncated dUTPase. The results suggest that (i) closing of the active site during the catalytic cycle, through the movement of the C-terminal arm, requires the presence of the complete triphosphate moiety of the substrate in complex with Mg2+, and (ii) after catalytic cleavage the active site pops open to facilitate product release. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
dUTP pyrophosphatase, Non-hydrolyzable substrate analogue, Circular dichroism spectroscopy, Flexible C-terminal arm, Motif 5, Escherichia coli
in
FEBS Letters
volume
421
issue
1
pages
83 - 88
publisher
Wiley-Blackwell
external identifiers
  • scopus:0032472214
ISSN
1873-3468
DOI
10.1016/S0014-5793(97)01545-7
language
English
LU publication?
yes
id
bcdca115-e16a-48d6-89bc-b9d8201f2ec1 (old id 125625)
date added to LUP
2016-04-01 17:12:27
date last changed
2022-01-29 01:06:21
@article{bcdca115-e16a-48d6-89bc-b9d8201f2ec1,
  abstract     = {{The molecular mechanism of substrate analogue interaction with Escherichia coli dUTPase was investigated, using the non-hydrolyzable 2'-deoxyuridine 5'-(α,β-imido)triphosphate (α,β-imido-dUTP). Binding of this analogue induces a difference in the far UV circular dichroism (CD) spectrum arguing for a significant change in protein conformation. The spectral shift is strictly Mg2+-dependent, does not appear with dUDP instead of α,β-imido-dUTP and is not elicited if the flexible C-terminal arm is deleted from the protein by limited tryptic digestion. Involvement of the C-terminal arm in α,β-imido-dUTP binding is consistent with the finding that this analogue protects against tryptic hydrolysis at Arg-141. Near UV CD of ligand-enzyme complexes reveals a characteristic difference in the microenvironments of enzyme-bound dUDP and α,β-imido-dUTP, a difference not observable in C-terminally truncated dUTPase. The results suggest that (i) closing of the active site during the catalytic cycle, through the movement of the C-terminal arm, requires the presence of the complete triphosphate moiety of the substrate in complex with Mg2+, and (ii) after catalytic cleavage the active site pops open to facilitate product release.}},
  author       = {{Vertessy, Beata G. and Larsson, Gunilla and Persson, Tina and Bergman, Anna-Carin and Persson, Rebecca and Nyman, Per-Olof}},
  issn         = {{1873-3468}},
  keywords     = {{dUTP pyrophosphatase; Non-hydrolyzable substrate analogue; Circular dichroism spectroscopy; Flexible C-terminal arm; Motif 5; Escherichia coli}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{83--88}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{FEBS Letters}},
  title        = {{The complete triphosphate moiety of non-hydrolyzable substrate analogues is required for a conformational shift of the flexible C-terminus in E. coli dUTP pyrophosphatase}},
  url          = {{http://dx.doi.org/10.1016/S0014-5793(97)01545-7}},
  doi          = {{10.1016/S0014-5793(97)01545-7}},
  volume       = {{421}},
  year         = {{1998}},
}