Identification of carboxylation enzymes and characterization of a novel four-subunit pyruvate:flavodoxin oxidoreductase from Helicobacter pylori.

ABSTRACT: The enzyme activities responsible for carboxylation reactions in cell extracts of the gastric pathogen Helicobacter pylori have been studied by H14CO3- fixation and spectrophotometric assays. Acetyl coenzyme A carboxylase (EC 6.4.1.2) and malic enzyme (EC 1.1.1.40) activities were detected, whereas pyruvate carboxylase (EC 6.4.1.1), phosphoenolpyruvate carboxylase (EC 4.1.3.1) and phosphoenolpyruvate carboxykinase (EC 4.1.1.49) activities were absent. However, a pyruvate-dependent, ATP-independent, and avidin-insensitive H14CO3- fixation activity, which was shown to be due to the isotope exchange reaction of pyruvate:flavodoxin oxidoreductase (EC 1.2.7.1), was present. The purified enzyme is composed of four subunits of 47, 36, 24, and 14 kDa. N-terminal sequence analysis showed that this

SUBMITTER: Hughes NJ 

PROVIDER: S-EPMC177123 | biostudies-literature | 1995 Jul

REPOSITORIES: biostudies-literature