Characterization of the recombinant diaminobutyric acid acetyltransferase from Methylophaga thalassica and Methylophaga alcalica.
Diaminobutyric acid acetyltransferase (EctA) catalyzes the acetylation of diaminobutyric acid to gamma-N-acetyl-alpha,gamma-diaminobutyrate with acetyl coenzyme A. This is the second reaction in the ectoine biosynthetic pathway. The recombinant EctA proteins were purified from two moderately halophilic methylotrophic bacteria: Methylophaga thalassica ATCC 33146T and Methylophaga alcalica ATCC 35842T. EctA found in both methylotrophs is a homodimer with a subunit molecular mass of c. 20 kDa and had similar properties with respect to the optimum temperature for activity (30 degrees C), Km for diaminobutyrate (370 or 375 microM) and the absence of requirements for divalent metal ions. The enzyme from M. thalassica exhibited a lower pH optimum and was inhibited both by sodium carbonates and by high ionic strength but to a lesser extent by copper ions.
Mustakhimov
Ildar I
II
Pushchino State University, Pushchino, Moscow region, Russia.
Rozova
Olga N
ON
Reshetnikov
Alexander S
AS
Khmelenina
Valentina N
VN
Murrell
J Colin
JC
Trotsenko
Yuri A
YA
D000123:Acetyltransferases / Q000096:biosynthesis*; D002254:Carbonates / Q000378:metabolism; D002413:Cations, Divalent; D003001:Cloning, Molecular; D003300:Copper / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009994:Osmolar Concentration; D044147:Piscirickettsiaceae / Q000201:enzymology*; D011189:Potassium Chloride / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D012965:Sodium Chloride / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
D002254:Carbonates; D002413:Cations, Divalent; D011994:Recombinant Proteins; D012965:Sodium Chloride; C005686:sodium carbonate; D011189:Potassium Chloride; D003300:Copper; C106232:2,4-diaminobutyric acid acetyltransferase; D000123:Acetyltransferases