HMM Summary Page: TIGR02006

Functioncysteine desulfurase IscS
Gene SymboliscS
Trusted Cutoff643.20
Domain Trusted Cutoff643.20
Noise Cutoff621.90
Domain Noise Cutoff621.90
Isology Typeequivalog
EC Number2.8.1.7
HMM Length402
Mainrole CategoryBiosynthesis of cofactors, prosthetic groups, and carriers
Subrole CategoryOther
Gene Ontology TermGO:0016226: iron-sulfur cluster assembly biological_process
GO:0031071: cysteine desulfurase activity molecular_function
AuthorHaft DH
Entry DateOct 2 2003 1:41PM
Last ModifiedFeb 14 2011 3:27PM
CommentThis HMM represents IscS, one of several cysteine desulfurases from a larger protein family designated (misleadingly, in this case) class V aminotransferases. IscS is one of at least 6 enzymes characteristic of the IscSUA-hscAB-fsx system of iron-sulfur cluster assembly. Scoring almost as well as proteobacterial sequences included in the model are mitochondrial cysteine desulfurases, apparently from an analogous system in eukaryotes. The sulfur, taken from cysteine, may be used in other systems as well, such as tRNA base modification and biosynthesis of other cofactors.
ReferencesRN [1] RM 14978044 RT Substitutions in an active site loop of Escherichia coli IscS result in specific defects in Fe-S cluster and thionucleoside biosynthesis in vivo. RA Lauhon CT, Skovran E, Urbina HD, Downs DM, Vickery LE. RL J Biol Chem. 2004 May 7;279(19):19551-8. RN [2] RM PMID: 16387657 RT Mechanistic insights into sulfur relay by multiple sulfur mediators involved in thiouridine biosynthesis at tRNA wobble positions. RA Ikeuchi Y, Shigi N, Kato J, Nishimura A, Suzuki T RL Mol Cell. 2006 Jan 6;21(1):97-108. DR HAMAP; MF_00331; 93 of 104
Genome PropertyGenProp0138: iron-sulfur cluster assembly iscSUA-hscBA-fdx system (HMM)
GenProp0704: tRNA U34 carboxymethylaminomethyl modification (HMM)