MetaCyc Enzyme: halimadienyl-diphosphate synthase

Gene: Rv3377c Accession Number: G-10682 (MetaCyc)

Species: Mycobacterium tuberculosis H37Rv

The Rv3377c gene of Mycobacterium tuberculosis was cloned, functionally expressed in Escherichia coli, and the expressed protein was subjected to the enzymic reactions using various substrates of terpenoid cyclases [Nakano05]. The enzyme catalyzed the cyclization of geranylgeranyl diphosphate to tuberculosinyl diphosphate, an intermediate that was immediately dephosphorylated to tuberculosinol by a phosphatase.

The reaction catalyzed by halimadienyl-diphosphate synthase proceeds in a pre chair-chair conformation to give a bicyclic intermediate which is then converted to tuberculosinyl diphosphate by a series of 1,2-shift reactions of hydride and methyl groups in antiparallel fashion, followed by deprotonation of H6, introducing a double bond at C5-C6.

The biological function of these prducts is not known, but the fact that the Rv3377c gene is only present in pathogenic species suggests that it may be involved in pathogenicity [Nakano05].

Molecular Weight of Polypeptide: 55.262 kD (from nucleotide sequence)

Unification Links: Entrez-gene:888073 , Pride:O50406 , Protein Model Portal:O50406 , SMR:O50406 , String:83332.Rv3377c , UniProt:O50406

Relationship Links: InterPro:IN-FAMILY:IPR008930

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 14-May-2008 by Caspi R , SRI International

Enzymatic reaction of: halimadienyl-diphosphate synthase

EC Number:

geranylgeranyl diphosphate <=> tuberculosinyl diphosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: tuberculosinol biosynthesis

Activators (Allosteric): Mg2+ [Nakano05]


Nakano05: Nakano C, Okamura T, Sato T, Dairi T, Hoshino T (2005). "Mycobacterium tuberculosis H37Rv3377c encodes the diterpene cyclase for producing the halimane skeleton." Chem Commun (Camb) NIL(8);1016-8. PMID: 15719101

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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 Tue Oct 6, 2015, BIOCYC14A.