ABSTRACT
In vivo expression of CO dehydrogenase/acetyl coenzyme A synthase in Methanosarcina spp. is coordinately regulated in response to substrate by at least two mechanisms: differential transcription initiation and early elongation termination near the 3' end of a 371-bp leader sequence. This is the first report of regulation of transcription elongation in the Archaea.
Subject(s)
Aldehyde Oxidoreductases/physiology , Methanosarcina/enzymology , Methanosarcina/genetics , Multienzyme Complexes/physiology , 5' Untranslated Regions/genetics , 5' Untranslated Regions/physiology , Aldehyde Oxidoreductases/genetics , Archaeal Proteins/genetics , Archaeal Proteins/physiology , Base Sequence , Gene Expression Regulation, Archaeal/genetics , Molecular Sequence Data , Multienzyme Complexes/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Nucleic Acid , Transcription, Genetic/geneticsABSTRACT
A recombinant protein overproduction system was developed in Methanosarcina acetivorans to facilitate biochemical characterization of oxygen-sensitive metalloenzymes from strictly anaerobic species in the Archaea domain. The system was used to overproduce the archetype of the independently evolved gamma-class carbonic anhydrase. The overproduced enzyme was oxygen sensitive and had full incorporation of iron instead of zinc observed when overproduced in Escherichia coli. This, the first report of in vivo iron incorporation for any carbonic anhydrase, supports the need to reevaluate the role of iron in all classes of carbonic anhydrases derived from anaerobic environments.
