electron transport SCO1/SenC family protein; IPR003782 (Copper chaperone SCO1/SenC), IPR012336 (Thioredoxin-like fold); GO:0005507 (copper ion binding), GO:0005743 (mitochondrial inner membrane), GO:0006825 (copper ion transport), GO:0006878 (cellular copper ion homeostasis), GO:0008535 (respiratory chain complex IV assembly)