TY  - JOUR
AU  - Samygina, V. R.
AU  - Moiseev, V. M.
AU  - Rodina, E. V.
AU  - Vorobyeva, N. N.
AU  - Popov, A. N.
AU  - Kurilova, S. A.
AU  - Nazarova, T. I.
AU  - Avaeva, S. M.
AU  - Bartunik, H. D.
AU  - DESY
TI  - Reversible inhibition of Escherichia coli inorganic pyrophosphatase by fluoride: trapped catalytic intermediates in cryo-crystallographic studies
JO  - Journal of molecular biology
VL  - 366
SN  - 0022-2836
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - PHPPUBDB-6428
SP  - 1305-1317
PY  - 2007
AB  - Here, we describe high-resolution X-ray structures of Escherichia coli inorganic pyrophosphatase (E-PPase) complexed with the substrate, magnesium, or manganese pyrophosphate. The structures correspond to steps in the catalytic synthesis of enzyme-bound pyrophosphate (PP(i)) in the presence of fluoride as an inhibitor of hydrolysis. The catalytic reaction intermediates were trapped applying a new method that we developed for initiating hydrolytic activity in the E-PPase crystal. X-ray structures were obtained for three consecutive states of the enzyme in the course of hydrolysis. Comparative analysis of these structures showed that the Mn2+-supported hydrolysis of the phosphoanhydride bond is followed by a fast release of the leaving phosphate from the P1 site. The electrophilic phosphate P2 is trapped in the "down" conformation. Its movement into the üp" position most likely represents the rate-limiting step of Mn2+-supported hydrolysis. We further determined the crystal structure of the Arg43Gln mutant variant of E-PPase complexed with one phosphate and four Mn ions.
KW  - Binding Sites
KW  - Catalysis
KW  - Diphosphates: chemistry
KW  - Diphosphates: pharmacology
KW  - Enzyme Activation
KW  - Escherichia coli: enzymology
KW  - Fluorides: chemistry
KW  - Fluorides: pharmacology
KW  - Hydrogen-Ion Concentration
KW  - Hydrolysis
KW  - Inorganic Pyrophosphatase: chemistry
KW  - Inorganic Pyrophosphatase: genetics
KW  - Inorganic Pyrophosphatase: metabolism
KW  - Magnesium: chemistry
KW  - Magnesium: pharmacology
KW  - Manganese: chemistry
KW  - Manganese: pharmacology
KW  - Models, Molecular
KW  - Mutation
KW  - Protein Isoforms
KW  - Substrate Specificity
KW  - X-Ray Diffraction: methods
KW  - Diphosphates (NLM Chemicals)
KW  - Fluorides (NLM Chemicals)
KW  - Protein Isoforms (NLM Chemicals)
KW  - Magnesium (NLM Chemicals)
KW  - Manganese (NLM Chemicals)
KW  - Inorganic Pyrophosphatase (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:17196979
UR  - <Go to ISI:>//WOS:000244649500021
DO  - DOI:10.1016/j.jmb.2006.11.082
UR  - https://bib-pubdb1.desy.de/record/81600
ER  -