Analyses of Three Dominant Membrane Proteins from Anammox Planctomycete Candidatus 'Brocadia sinica'

Anammox planctomycetes commonly possess a unique single membrane-bound organelle, the anammoxosome, that harbors enzymes central to anaerobic ammonia oxidation, anammox, metabolism. We found that three membrane proteins, namely P35, P45, or P90, were dominantly produced in Candidatus ‘Brocadia sinica,’ an anammox planctomycete that has been obtained from an eff ective anammox reactor. N-terminal amino acid sequences suggested that all these three are components of hydrazine hydrolase which is a key enzyme in anammox metabolism. The genes encoding for P35, P45, and P90 formed a cluster preceded by sigma54 specifi c two-component regulator proteins. Heterologous gene expression of P35, P45 and P90 conferred high biofi lm formation ability to the E. coli cells, suggesting that they were transported to cell membrane of E. coli and the membrane structure was modifi ed to increase cell adhesion activity.