Disease relevance of ECs5204

• Replacements of His21 and His86 in mtPPase with the residues found in the corresponding positions of E. coli PPase had either no effect on the Mg2+- and Mn2+-supported reactions (H86K) or reduced Mg2+-supported activity (H21K) [1].
• Here, we report the structural and functional characterization of a unique family I PPase from Mycobacterium tuberculosis (mtPPase) that has two His residues (His21 and His86) in the active site [1].
• Pyrophosphatase (PPase) from Bacillus subtilis has recently been found to be the first example of a family II soluble PPase with a unique requirement for Mn2+ [2].
• A protein phosphatase (PPase) from the bacteriophage lambda was overexpressed in Escherichia coli [3].
• This suggests that B. subtilis PPase represents a new family of soluble PPases (a Bs family), putative members of which were found in Archaeoglobus fulgidus, Methanococcus jannaschii, Streptococcus mutans and Streptococcus gordonii [4].

High impact information on ECs5204

• Otherwise, mtPPase is structurally very similar to the well studied family I hexameric PPase from Escherichia coli, although mtPPase lacks the intersubunit metal binding site found in E. coli PPase [1].
• The hydrolytic activity of H(+)-PPase in E. coli vesicles was eight times greater than that in R. rubrum chromatophores but exhibited similar sensitivity to the H(+)-PPase inhibitor, aminomethylenediphosphonate, and insensitivity to the soluble PPase inhibitor, fluoride [5].
• Each of the five histidines in Escherichia coli inorganic pyrophosphatase (PPase) was replaced in turn by glutamine [6].
• Asp142 in the homotetrameric ADP-glucose pyrophosphorylase (ADP-Glc PPase) enzyme from Escherichia coli was demonstrated to be involved in catalysis of this enzyme [Frueauf, J.B., Ballicora, M.A. and Preiss J. (2001) J. Biol. Chem., 276, 46319-46325] [7].
• To investigate the function of these conserved Asp residues in the ADP-Glc PPase from potato tuber, we used site-directed mutagenesis to introduce either an Asn or a Glu [7].

Chemical compound and disease context of ECs5204

• Rabbit antiserum raised against the spinach leaf ADP-Glc PPase (but not the one raised against the enzyme from Escherichia coli) inhibited the activity of the purified algal enzyme, which migrated as a single protein band in native polyacrylamide gel electrophoresis [8].

Biological context of ECs5204

• Antisera raised against the spinach leaf holoenzyme and against the 51-kD spinach subunit cross-reacted with both subunits of the algal ADP-Glc PPase in immunoblot hybridization, but the cross-reaction was stronger for the 50-kD algal subunit than for the 53-kD subunit [8].
• A homolog to the eubacteria inorganic pyrophosphatase (PPase, EC 3.6.1.1) was found in the genome of the hyperthermophilic archaeon Pyrococcus horikoshii [9].
• At the same time, occupation of center IV eliminates the inhibition of inorganic pyrophosphate hydrolysis by high Mg2+ concentrations typical of wild-type PPase [10].
• Furthermore, the partial amino acid sequence (residues 1 to 108) of E. coli PPase determined by S [11].
• In exponentially growing cells the intracellular PPi concentration was in every case 1.5 nmol/mg (dry weight) or about 0.5 mM, even though the amount of PPase was varied from 15 to 2,600% of the control amount by mutation or by using a multicopy plasmid with an inserted gene (ppa) encoding PPase [12].

Associations of ECs5204 with chemical compounds

• The reasons for Ca(2+) being the strong PPase inhibitor and the role in catalysis of each of four metal ions are the mechanistic aspects discussed on the basis of the structures described [13].
• Each of two histidine residues and one tryptophan residue in thermophilic bacterium PS-3 inorganic pyrophosphatase (PPase) was replaced by alanine [14].
• Adenosine 5'-diphosphate (ADP)-glucose pyrophosphorylase (ADP-Glc PPase) catalyzes the conversion of glucose 1-phosphate and adenosine 5'-triphosphate to ADP-glucose and pyrophosphate [15].
• Each of the 10 proline residues of the inorganic pyrophosphatase (PPase) subunit of thermophilic bacterium PS-3 (PS-3) was replaced with alanine by the PCR-mutagenesis method [16].
• Guanidine hydrochloride-induced chemical denaturation of PPase has also been studied [17].

Analytical, diagnostic and therapeutic context of ECs5204

• In contrast to wild-type PPase, which is hexameric, these variants can be dissociated into trimers by dilution, as shown by analytical ultracentrifugation and cross-linking [6].
• The recombinant PPase from P. horikoshii (PhPPase) has a molecular mass of 24.5 kDa, determined by SDS-PAGE [18].
• Differential scanning calorimetry has been used to determine the apparent enthalpy of thermal denaturation for the native PPase and its mutant variants Gly100Ala and Gly147Val [17].

References