A new widespread subclass of carbonic anhydrase in marine phytoplankton

Most aquatic photoautotrophs depend on CO2-concentrating mechanisms (CCMs) to maintain productivity at ambient concentrations of CO2, and carbonic anhydrase (CA) plays a key role in these processes. Here we present different lines of evidence showing that the protein LCIP63, identified in the marine diatom Thalassiosira pseudonana, is a CA. However, sequence analysis showed that it has a low identity with any known CA and therefore belongs to a...