HMM Summary Page: TIGR03658

Functionhaptoglobin-binding heme uptake protein HarA
Trusted Cutoff1400.25
Domain Trusted Cutoff1400.25
Noise Cutoff1044.00
Domain Noise Cutoff1044.00
Isology Typeequivalog
HMM Length895
Gene Ontology TermGO:0020037: heme binding molecular_function
AuthorSelengut J
Entry DateSep 4 2008 12:06PM
Last ModifiedFeb 14 2011 3:27PM
CommentHarA is a heme-binding NEAT-domain (NEAr Transporter, PF05031) protein which has been shown to bind to the haptoglobin-hemoglobin complex in order to extract heme from it. HarA has also been reported to bind hemoglobin directly [2]. HarA (also known as IsdH) contains three NEAT domains as well as a sortase A C-terminal signal for localization to the cell wall. The heme bound at the third of these NEAT domains has been shown to be transferred to the IsdA protein also localized at the cell wall, presumably through an additional specific protein-protein interaction [3]. Haptoglobin is a hemoglobin carrier protein involved in scavenging hemoglobin in the blood following red blood cell lysis and targetting it to the liver.
ReferencesRN [1] RM PMID:17041047 RT High-affinity binding of the staphylococcal HarA protein to haptoglobin and hemoglobin involves a domain with an antiparallel eight-stranded beta-barrel fold. RA Dryla A, Hoffmann B, Gelbmann D, Giefing C, Hanner M, Meinke A, Anderson AS, Koppensteiner W, Konrat R, von Gabain A, Nagy E RL J Bacteriol. 2007 Jan;189(1):254-64. Epub 2006 Oct 13. RN [2] RM PMID:16762363 RT Solution structure of the NEAT (NEAr Transporter) domain from IsdH/HarA: the human hemoglobin receptor in Staphylococcus aureus. RA Pilpa RM, Fadeev EA, Villareal VA, Wong ML, Phillips M, Clubb RT RL J Mol Biol. 2006 Jul 7;360(2):435-47. Epub 2006 May 22. RN [3] RM PMID:18676371 RT Demonstration of the iron-regulated surface determinant heme transfer pathway in Staphylococcus aureus. RA Muryoi N, Tiedemann MT, Pluym M, Cheung J, Heinrichs DE, Stillman MJ RL J Biol Chem. 2008 Aug 1.
Genome PropertyGenProp0828: heme uptake system, NEAT-domain mediated (HMM)