Inorganic pyrophosphatases of Family II-two decades after their discovery.
FEBS Lett
; 591(20): 3225-3234, 2017 10.
Article
in En
| MEDLINE
| ID: mdl-28986979
ABSTRACT
Inorganic pyrophosphatases (PPases) convert pyrophosphate (PPi ) to phosphate and are present in all cell types. Soluble PPases belong to three nonhomologous families, of which Family II is found in approximately a quarter of prokaryotic organisms, often pathogenic ones. Each subunit of dimeric canonical Family II PPases is formed by two domains connected by a flexible linker, with the active site located between the domains. These enzymes require both magnesium and a transition metal ion (manganese or cobalt) for maximal activity and are the most active (kcat ≈ 104 s-1 ) among all PPase types. Catalysis by Family II PPases requires four metal ions per substrate molecule, three of which form a unique trimetal center that coordinates the nucleophilic water and converts it to a reactive hydroxide ion. A quarter of Family II PPases contain an autoinhibitory regulatory insert formed by two cystathionine ß-synthase (CBS) domains and one DRTGG domain. Adenine nucleotide binding either activates or inhibits the CBS domain-containing PPases, thereby tuning their activity and, hence, PPi levels, in response to changes in cell energy status (ATP/ADP ratio).
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacteria
/
Protein Subunits
/
Inorganic Pyrophosphatase
/
Eukaryotic Cells
/
Magnesium
Language:
En
Journal:
FEBS Lett
Year:
2017
Document type:
Article
Affiliation country:
RUSSIA