1HM4

N219L PENTALENENE SYNTHASE

Summary for 1HM4

• Entry DOI: 10.2210/pdb1hm4/pdb
• Related: 1HM7
• Descriptor: PENTALENENE SYNTHASE (1 entity in total)
• Functional Keywords: sesquiterpene synthase, pentalenene, terpene, antibiotic biosynthesis, lyase
• Biological source: Streptomyces sp.
• Total number of polymer chains: 2
• Total formula weight: 75836.55

Authors

Seemann, M.,Paschall, C.M.,Christianson, D.W.,Cane, D.E. (deposition date: 2000-12-04, release date: 2002-08-30, Last modification date: 2024-10-30)

Primary citation

Seemann, M.,Zhai, G.,de Kraker, J.W.,Paschall, C.M.,Christianson, D.W.,Cane, D.E.
Pentalenene synthase. Analysis of active site residues by site-directed mutagenesis.
J.Am.Chem.Soc., 124:7681-7689, 2002

PubMed 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.

PubMed: 12083921
DOI: 10.1021/ja026058q

Experimental method

X-RAY DIFFRACTION (3.47 Å)