The carbamate kinase-like carbamoyl phosphate synthetase of the hyperthermophilic archaeon Pyrococcus furiosus, a missing link in the evolution of carbamoyl phosphate biosynthesis.

ABSTRACT: Microbial carbamoyl phosphate synthetases (CPS) use glutamine as nitrogen donor and are composed of two subunits (or domains), one exhibiting glutaminase activity, the other able to synthesize carbamoyl phosphate (CP) from bicarbonate, ATP, and ammonia. The pseudodimeric organization of this synthetase suggested that it has evolved by duplication of a smaller kinase, possibly a carbamate kinase (CK). In contrast to other prokaryotes the hyperthermophilic archaeon Pyrococcus furiosus was found to synthesize CP by using ammonia and not glutamine. We have purified the cognate enzyme and found it to be a dimer of two identical subunits of Mr 32,000. Its thermostability is considerable, 50% activity being retained after 1 h at 100 degrees C or 3 h at 95 degrees C. The corresponding gene was clo

SUBMITTER: Durbecq V 

PROVIDER: S-EPMC24219 | biostudies-literature | 1997 Nov

REPOSITORIES: biostudies-literature