Proposed pathway of methane oxidation in Methylococcus capsulatus cells producing either sMMO or pMMO. Proteins showing positive or negative Cu regulation are shown in blue and red, respectively. Proteins not showing a Cu regulation or have low expression values (based on microarray data) are shown in white and gray, respectively. c‐type cytochromes are shown in green. NQR, Na+‐translocating NADH‐quinone reductase; NDH‐2, type 2 NADH dehydrogenase; FQR, formaldehyde‐quinone reductase; NDH‐1, type 1 NADH dehydrogenase; QCR, quinol‐cytochrome c reductase; PMMO, particulate methane monooxygenase; SMMO, soluble methane monooxygenase; MDH, methanol dehydrogenase; CAA, cytochrome caa
3; CBD, cytochrome cbd; HPP, H+‐translocating pyrophosphatase; ATP, ATPase.