ARMCX5 is an armadillo repeat–containing protein that is encoded by the X-linked ARMCX5 gene. It is conserved only in Eutheria,[5] a specific group of placental mammals, but no further back in evolutionary time. ARMCX5 contains 3 ARM-like repeats, DUF364, and ARM-type fold.[6]
Proteins containing this ARMCX5 domain interact with numerous other proteins. Through these interactions, they are involved in a wide variety of processes including carcinogenesis, control of cellular ageing and survival, regulation f circadian rhythm and lysosomal sorting of G-protein coupled receptors.[6]
Because DUF364 contains a PLP-dependent transferase-like fold, the genomic context suggests that it may have a role in anaerobic vitamin B12 biosynthesis.[9]