hbd hbd hemoglobin subunit delta is a protein that in humans is encoded by the hbd gene. hbdavailable structurespdbhuman uniprot search: pdbe rcsb list of pdb id codes1shr, 1si4identifiersaliaseshbd, hemoglobin subunit deltaexternal idsomim: 142000 homologene: 128037 genecards: hbd gene location (human)chr.chromosome 11 (human)band11p15.4start5,232,678 bpend5,243,657 bprna expression patternbgeehumanmouse (ortholog)top expressed incancellous bonebone marrowbone marrow cellsmonocytebloodvena cavaendothelial cellperiodontal fiberspleensuperficial temporal arteryn/amore reference expression databiogpsn/agene ontologymolecular function iron ion binding oxygen binding protein binding heme binding metal ion binding oxygen carrier activity peroxidase activity haptoglobin binding hemoglobin alpha binding organic acid binding cellular component hemoglobin complex cytosol blood microparticle haptoglobin-hemoglobin complex biological process oxygen transport blood coagulation transport hydrogen peroxide catabolic process protein heterooligomerization cellular oxidant detoxification sources:amigo / quickgoorthologsspecieshumanmouseentrez3045n/aensemblensg00000223609n/auniprotp02042n/arefseq (mrna)nm_000519n/arefseq (protein)np_000510n/alocation (ucsc)chr 11: 5.23 – 5.24 mbn/apubmed searchn/awikidataview/edit human function the delta (hbd) and beta (hbb) genes are normally expressed in the adult: two alpha chains plus two beta chains constitute hba, which in normal adult life comprises about 97% of the total hemoglobin. two alpha chains plus two delta chains constitute hba2, which with hbf comprises the remaining 3% of adult hemoglobin. five beta-like globin genes are found within a 45 kb cluster on chromosome 11 in the following order: 5' - epsilon – gamma-g – gamma-a – delta – beta - 3'. clinical significance mutations in the delta-globin gene are associated with delta-thalassemia.