English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Background  Carbonic anhydrase (CA) is a ubiquitous enzyme catalyzing the reversible hydration of CO 2  to bicarbonate, a reaction underlying diverse biochemical and physiological processes. Gamma class carbonic anhydrases (γ-CAs) are widespread in prokaryotes but their physiological roles remain elusive. At present, only γ-CA of  Methanosarcina thermophila  (Cam) has been shown to have CA activity. Genome analysis of a rhizobacterium  Azospirillum brasilense , revealed occurrence of ORFs encoding one β-CA and two γ-CAs.    Results  One of the putative γ-CA encoding genes of  A. brasilense  was cloned and overexpressed in  E. coli . Electrometric assays for CA activity of the whole cell extracts overexpressing recombinant GCA1 did not show CO 2  hydration activity. Reverse transcription-PCR analysis indicated that  gca1  in  A. brasilense  is co-transcribed with its upstream gene annotated as  argC , which encodes a putative  N -acetyl-γ-glutamate-phosphate reductase. 5'-RACE also demonstrated that there was no transcription start site between  argC  and  gca1 , and the transcription start site located upstream of  argC  transcribed both the genes ( argC-gca1 ). Using transcriptional fusions of  argC - gca1  upstream region with promoterless  lacZ , we further demonstrated that  gca1  upstream region did not have any promoter and its transcription occurred from a promoter located in the  argC  upstream region. The transcription of  argC-gca1  operon was upregulated in stationary phase and at elevated CO 2  atmosphere.    Conclusions  This study shows lack of CO 2  hydration activity in a recombinant protein expressed from a gene predicted to encode a γ-carbonic anhydrase in  A. brasilense  although it cross reacts with anti-Cam antibody raised against a well characterized γ-CA. The organization and regulation of this gene along with the putative  argC  gene suggests its involvement in arginine biosynthetic pathway instead of the predicted CO 2  hydration.

Gene encoding γ-carbonic anhydrase is cotranscribed with argC and induced in response to stationary phase and high CO2 in Azospirillum brasilense Sp7