PDBsum entry 2j5c

Lyase

PDB id: 2j5c

Contents

Protein chains

485 a.a. *

Ligands

BME ×4

Waters ×459

* Residue conservation analysis

PDB id:

2j5c

Name:

Lyase

Title:

Rational conversion of substrate and product specificity in a monoterpene synthase. Structural insights into the molecular basis of rapid evolution.

Structure:

1,8-cineole synthase. Chain: a, b. Fragment: residues 58-591. Engineered: yes

Source:

Salvia fruticosa. Greek sage. Organism_taxid: 268906. Strain: m. Skoula 824 (tuccg). Expressed in: escherichia coli. Expression_system_taxid: 511693. Other_details: wild source found in nio chorio, chania, crete, greece

Resolution:

1.95Å R-factor: 0.218 R-free: 0.235

Authors:

S.C.Kampranis,D.Ioannidis,A.Purvis,W.Mahrez,E.Ninga,N.A.Katerelos, S.Anssour,J.M.Dunwell,A.M.Makris,P.W.Goodenough,C.B.Johnson

Key ref:

S.C.Kampranis et al. (2007). Rational conversion of substrate and product specificity in a Salvia monoterpene synthase: structural insights into the evolution of terpene synthase function. Plant Cell, 19, 1994-2005. PubMed id: 17557809

Date:

14-Sep-06 Release date: 26-Jun-07

Protein chains

A6XH05  (CINS1_SALFT) -  Cineole synthase 1, chloroplastic from Salvia fruticosa

Seq: 591 a.a.

Struc: 485 a.a.

Enzyme reactions

• Enzyme class 2: E.C.4.2.3.- - ?????
• Enzyme class 3: E.C.4.2.3.108 - 1,8-cineole synthase.
• Reaction: (2E)-geranyl diphosphate + H2O = 1,8-cineole + diphosphate
• Cofactor: Zn(2+) or Mn(2+)
• Enzyme class 4: E.C.4.2.3.111 - (-)-alpha-terpineol synthase.
• Reaction: (2E)-geranyl diphosphate + H2O = (S)-alpha-terpineol + diphosphate
• Enzyme class 5: E.C.4.2.3.15 - myrcene synthase.

Pathway:

• Reaction: (2E)-geranyl diphosphate = beta-myrcene + diphosphate
• Cofactor: K(+); Mn(2+)

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

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

reference

Plant Cell 19:1994-2005 (2007)

PubMed id: 17557809

Rational conversion of substrate and product specificity in a Salvia monoterpene synthase: structural insights into the evolution of terpene synthase function.

S.C.Kampranis, D.Ioannidis, A.Purvis, W.Mahrez, E.Ninga, N.A.Katerelos, S.Anssour, J.M.Dunwell, J.Degenhardt, A.M.Makris, P.W.Goodenough, C.B.Johnson.

ABSTRACT

Terpene synthases are responsible for the biosynthesis of the complex chemical defense arsenal of plants and microorganisms. How do these enzymes, which all appear to share a common terpene synthase fold, specify the many different products made almost entirely from one of only three substrates? Elucidation of the structure of 1,8-cineole synthase from Salvia fruticosa (Sf-CinS1) combined with analysis of functional and phylogenetic relationships of enzymes within Salvia species identified active-site residues responsible for product specificity. Thus, Sf-CinS1 was successfully converted to a sabinene synthase with a minimum number of rationally predicted substitutions, while identification of the Asn side chain essential for water activation introduced 1,8-cineole and alpha-terpineol activity to Salvia pomifera sabinene synthase. A major contribution to product specificity in Sf-CinS1 appears to come from a local deformation within one of the helices forming the active site. This deformation is observed in all other mono- or sesquiterpene structures available, pointing to a conserved mechanism. Moreover, a single amino acid substitution enlarged the active-site cavity enough to accommodate the larger farnesyl pyrophosphate substrate and led to the efficient synthesis of sesquiterpenes, while alternate single substitutions of this critical amino acid yielded five additional terpene synthases.