PDBsum entry: 1hm7

Lyase

PDB id: 1hm7

Contents

Protein chains

284 a.a. *

305 a.a. *

Waters ×26

* Residue conservation analysis

PDB id:

1hm7

Name:

Lyase

Title:

N219l pentalenene synthase

Structure:

Pentalenene synthase. Chain: a, b. Engineered: yes. Mutation: yes

Source:

Streptomyces sp.. Organism_taxid: 74577. Strain: uc5319. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Hexamer (from PQS)

Resolution:

2.90Å R-factor: 0.263 R-free: 0.308

Authors:

M.Seemann,C.M.Paschall,D.W.Christianson,D.E.Cane

Key ref:

M.Seemann et al. (2002). Pentalenene synthase. Analysis of active site residues by site-directed mutagenesis. J Am Chem Soc, 124, 7681-7689. PubMed id: 12083921 DOI: 10.1021/ja026058q

Date:

05-Dec-00 Release date: 30-Aug-02

Protein chain

Q55012  (PTLS_STRS3) -  Pentalenene synthase

Seq: 337 a.a.

Struc: 284 a.a.*

Protein chain

Q55012  (PTLS_STRS3) -  Pentalenene synthase

Seq: 337 a.a.

Struc: 305 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chains A, B: E.C.4.2.3.7 - Pentalenene synthase.
• Pathway: Humulene derived sesquiterpenoid biosynthesis
• Reaction: (2E,6E)-farnesyl diphosphate = pentalenene + diphosphate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

 Gene Ontology (GO) functional annotation 

• Biological process: antibiotic biosynthetic process (1 term)
• Biochemical function: lyase activity (5 terms)

reference

DOI no: 10.1021/ja026058q

J Am Chem Soc 124:7681-7689 (2002)

PubMed id: 12083921

Pentalenene synthase. Analysis of active site residues by site-directed mutagenesis.

M.Seemann, G.Zhai, J.W.de Kraker, C.M.Paschall, D.W.Christianson, D.E.Cane.

ABSTRACT

Incubation of farnesyl diphosphate (1) with the W308F or W308F/H309F mutants of pentalenene synthase, an enzyme from Streptomyces UC5319, yielded pentalenene (2), accompanied by varying proportions of (+)-germacrene A (7) with relatively minor changes in k(cat) and k(cat)/K(m). By contrast, single H309 mutants gave rise to both (+)-germacrene A (7) and protoilludene (8) in addition to pentalenene (2). Mutation to glutamate of each of the three aspartate residues in the Mg(2+)-binding aspartate-rich domain, (80)DDLFD, resulted in reduction in the k(cat)/K(m) for farnesyl diphosphate and formation of varying proportions of pentalenene and (+)-germacrene A (7). Formation of (+)-germacrene A (7) by the various pentalenene synthase mutants is the result of a derailment of the natural anti-Markovnikov cyclization reaction, and not simply the consequence of trapping of a normally cryptic, carbocationic intermediate. Both the N219A and N219L mutants of pentalenene synthase were completely inactive, while the corresponding N219D mutant had a k(cat)/K(m) which was 3300-fold lower than that of the wild-type synthase, and produced a mixture of pentalenene (2) (91%) and the aberrant cyclization product beta-caryophyllene (9) (9%). Finally, the F77Y mutant had a k(cat)/K(m) which was reduced by 20-fold compared to that of the wild-type synthase.