MetaCyc Enzyme: isopentenyl-diphosphate δ-isomerase

Gene: fni Accession Number: G-11191 (MetaCyc)

Synonyms: idi

Species: Sulfolobus shibatae

Subunit composition of isopentenyl-diphosphate δ-isomerase = [Fni]4
         isopentenyl-diphosphate δ-isomerase monomer = Fni

Isopentenyl-diphosphate δ-isomerase is an essential enzyme for organisms that utilize the mevalonate pathway. Two classes of the enzyme are known: type I enzymes have been known for a long time, and are widely distributed in eukaryota and eubacteria. Type II enzymes have been discovered relatively late, in Streptomyces sp. CL190 [Kaneda01].

Most of the archaebacteria possess type II enzymes. The fni gene of Sulfolobus shibatae, which encodes such as enzyme, has been cloned based on its similarity to the Streptomyces gene. The gene was expressed in Escherichia coli and purified to homogeneity [Yamashita04].

The enzyme, which forms a homotetramer, requires NAD(P)H and Mg2+ for activity, similar to its bacterial homologues. It is strictly dependent on FMN, and has NADH dehydrogenase activity, although it does not consume NADH during catalysis [Yamashita04].

Molecular Weight of Polypeptide: 40.427 kD (from nucleotide sequence)

Unification Links: Protein Model Portal:P61615 , UniProt:P61615

Relationship Links: Entrez-Nucleotide:PART-OF:AB118244 , InterPro:IN-FAMILY:IPR000262 , InterPro:IN-FAMILY:IPR011179 , InterPro:IN-FAMILY:IPR013785 , Panther:IN-FAMILY:PTHR10578:SF3 , PDB:Structure:2ZRU , PDB:Structure:2ZRV , PDB:Structure:2ZRW , PDB:Structure:2ZRX , PDB:Structure:2ZRY , PDB:Structure:2ZRZ , PDB:Structure:3B03 , PDB:Structure:3B04 , PDB:Structure:3B05 , PDB:Structure:3B06 , PDB:Structure:3VKJ , Pfam:IN-FAMILY:PF01070

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 23-Mar-2009 by Caspi R , SRI International

Enzymatic reaction of: isopentenyl-diphosphate δ-isomerase

EC Number:

isopentenyl diphosphate <=> dimethylallyl diphosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

This reaction is reversible. [Yamashita04]

In Pathways: mevalonate pathway II (archaea)

Cofactors or Prosthetic Groups: Mg2+ [Yamashita04], FMN [Yamashita04]

Kinetic Parameters:

Km (μM)
isopentenyl diphosphate

T(opt): 80 °C [Yamashita04]

pH(opt): 6 [Yamashita04]


Kaneda01: Kaneda K, Kuzuyama T, Takagi M, Hayakawa Y, Seto H (2001). "An unusual isopentenyl diphosphate isomerase found in the mevalonate pathway gene cluster from Streptomyces sp. strain CL190." Proc Natl Acad Sci U S A 98(3);932-7. PMID: 11158573

Yamashita04: Yamashita S, Hemmi H, Ikeda Y, Nakayama T, Nishino T (2004). "Type 2 isopentenyl diphosphate isomerase from a thermoacidophilic archaeon Sulfolobus shibatae." Eur J Biochem 271(6);1087-93. PMID: 15009187

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Wed Apr 1, 2015, BIOCYC13A.