This domain identifies a group of iron-regulated surface determinant proteins found exclusively in bacteria. Among them, the iron-regulated surface determinant protein H (isdH, also known as harA) binds human plasma haptoglobin-hemoglobin complexes, haptoglobin and hemoglobin. It binds haptoglobin-hemoglobin complexes with significantly higher affinity than haptoglobin alone [ expand

This domain identifies a group of iron-regulated surface determinant proteins found exclusively in bacteria. Among them, the iron-regulated surface determinant protein H (isdH, also known as harA) binds human plasma haptoglobin-hemoglobin complexes, haptoglobin and hemoglobin. It binds haptoglobin-hemoglobin complexes with significantly higher affinity than haptoglobin alone [ PUBMED:12823809 ]. In Staphylococcus aureus, isdH protein contains three NEAT (NEAr Transporter) domains: IsdH(N1), IsdH(N2), and IsdH(N3). These three domains have different functions, IsdH(N1) binds hemoglobin and haptoglobin, whereas IsdH(N3) captures heme that is released from hemoglobin [ PUBMED:18984582 PUBMED:16762363 ].