A cadmium enzyme from a marine diatom

Abstract
The ocean biota contains a vast reservoir of genomic diversity1. Here we present the sequence and preliminary characterization of a protein that is a cadmium-containing carbonic anhydrase from the marine diatom Thalassiosira weissflogii. The existence of a cadmium enzyme in marine phytoplankton may indicate that there is a unique selection pressure for metalloenzymes in the marine environment2, and our discovery provides a long-awaited explanation for the nutrient-like behaviour of cadmium in the oceans3.