HMM Summary Page: TIGR00049

Functioniron-sulfur cluster assembly accessory protein
Trusted Cutoff58.80
Domain Trusted Cutoff58.80
Noise Cutoff45.60
Domain Noise Cutoff45.60
Isology Typesubfamily
HMM Length106
Mainrole CategoryBiosynthesis of cofactors, prosthetic groups, and carriers
Subrole CategoryOther
Gene Ontology TermGO:0005198: structural molecule activity molecular_function
GO:0016226: iron-sulfur cluster assembly biological_process
AuthorRichardson DL, Haft DH
Entry DateApr 20 1999 2:04PM
Last ModifiedFeb 14 2011 3:27PM
CommentProteins in this subfamily appear to be associated with the process of FeS-cluster assembly. The HesB proteins are associated with the nif gene cluster and the Rhizobium gene IscN has been shown to be required for nitrogen fixation [1]. Nitrogenase includes multiple FeS clusters and many genes for their assembly. The E. coli SufA protein is associated with SufS, a NifS homolog and SufD which are involved in the FeS cluster assembly of the FhnF protein [2]. The Azotobacter protein IscA (homologs of which are also found in E.coli) is associated which IscS, another NifS homolog and IscU, a nifU homolog as well as other factors consistent with a role in FeS cluster chemistry [3]. A homolog from Geobacter contains a selenocysteine in place of an otherwise invariant cysteine, further suggesting a role in redox chemistry.
ReferencesRN [1] RM PMID: 12207230 RT The Rhizobium etli gene iscN is highly expressed in bacteroids and required for nitrogen fixation. RA Dombrecht B, Tesfay MZ, Verreth C, Heusdens C, Napoles MC, Vanderleyden J, Michiels J. RL Mol Genet Genomics 2002 Aug;267(6):820-8 RN [2] RM PMID: 10322040 RT SufS is a NifS-like protein, and SufD is necessary for stability of the [2Fe-2S] FhuF protein in Escherichia coli. RA Patzer SI, Hantke K. RL J Bacteriol 1999 May;181(10):3307-9 RN [3] RM PMID: 9582371 RT Assembly of iron-sulfur clusters. Identification of an iscSUA-hscBA-fdx gene cluster from Azotobacter vinelandii. RA Zheng L, Cash VL, Flint DH, Dean DR. RL J Biol Chem 1998 May 22;273(21):13264-72 SE TIGR DR HAMAP; MF_01429; 29 of 30