Changes in ATP sulfurylase activityin response to altered cyanobacteria growth conditions.

Abstract

Here we investigated variations in cell growth and ATP sulfurylase activity when two cyanobacterial strains - Synechocystis sp. PCC6803 and Synechococcus sp. WH7803 - were grown comparatively between conventional media and media with low ammonium, low sulfate and a controlled high CO2/low O2 atmosphere, which might resemble some Precambrian environments. In both organisms, a transition and adaptation to the reconstructed environmental media resulted in a decrease in ATPS specific activity. This decrease in activity appears to be decoupled from growth rate, suggesting the enzyme is not rate-limiting in S assimilation and raising questions about the role of ATPS redox regulation in cell physiology and thorughout history.