Acts early in chloroplast biogenesis as a component of a redox chain responsible for phytoene desaturation. Prevents the generation of toxic oxygen radicals and photooxidation of the nascent photosynthetic apparatus. Involved in the differentiation of multiple plastid types, including chloroplasts, amyloplasts, and etioplasts. Might participate in the chloroplast respiratory chain. 2 a ubiquinol + O2 = 2 a ubiquinone + 2 H2O Binds 2 iron ions per subunit. localized to the stromal thylakoid lamellae. Ubiquitous. Expressed throughout the development of the leaves. Variegated cotyledons and leaves. The amount of white tissue increases with light intensity. Belongs to the alternative oxidase family. Truncated N-terminus.