HMM Summary Page: TIGR03657

Functionheme uptake protein IsdB
Gene SymbolisdB
Trusted Cutoff1231.50
Domain Trusted Cutoff1231.50
Noise Cutoff766.85
Domain Noise Cutoff766.85
Isology Typeequivalog
HMM Length644
Gene Ontology TermGO:0020037: heme binding molecular_function
AuthorSelengut J
Entry DateSep 4 2008 10:19AM
Last ModifiedFeb 14 2011 3:27PM
CommentIsd proteins are iron-regulated surface proteins found in Bacillus, Staphylococcus and Listeria species and are responsible for heme scavenging from hemoproteins [1]. The IsdB protein is only observed in Staphylococcus and consists of an N-terminal hydrophobic signal sequence, a pair of tandem NEAT (NEAr Transporter, PF05031) domains which confers the ability to bind heme [2] and a C-terminal sortase processing signal which targets the protein to the cell wall. IsdB is believed to make a direct contact with methemoglobin facilitating transfer of heme to IsdB [3]. The heme is then transferred to other cell wall-bound NEAT domain proteins such as IsdA and IsdC.
ReferencesRN [1] 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. RN [2] RM PMID:17229211 RT Haem recognition by a Staphylococcus aureus NEAT domain. RA Grigg JC, Vermeiren CL, Heinrichs DE, Murphy ME RL Mol Microbiol. 2007 Jan;63(1):139-49. RN [3] RM PMID:18467329 RT Pathway for heme uptake from human methemoglobin by the iron-regulated surface determinants system of Staphylococcus aureus. RA Zhu H, Xie G, Liu M, Olson JS, Fabian M, Dooley DM, Lei B RL J Biol Chem. 2008 Jun 27;283(26):18450-60. Epub 2008 May 8.
Genome PropertyGenProp0828: heme uptake system, NEAT-domain mediated (HMM)