Cytoglobin gene is mapped onchromosome 17q25.1 that contains 4 exons with the spans of 9kb which comprises 190 amino acids in human and 174 amino acids in zebrafish where in mammalian genes displays a distinctive exon-intron pattern with an additional exon resulting in a C-terminal extension of the protein. In phylogenetic analyses implies that the cytoglobin has a common ancestor with vertebrates myoglobins that signifies vertebrates myoglobins evolved in adaptation for the special needs of the muscle.
Cytoglobin is highly expressed in heart, bladder, small intestine and stomach which is involved in intracellular oxygen movement. It plays an important role in enzymatic functions, oxygen sensing and detoxifying nitrogen oxide.
Cytoglobin is the fourth documented globin type that is universally distributed in human tissues. It also exhibits a core region of 150 residues that is structurally related to hemoglobin andmyoglobin with extra segments of 20 residues at the C- and N- terminal wherein a core region host a great apolar cavity seized to offer a ligand diffusion pathway from heme to ligand docking sites.
Gene name: CYGB
Protein name: Cytoglobin