Linked Life Data

8218177

Source:http://linkedlifedata.com/resource/pubmed/id/8218177

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
1993-11-26
pubmed:abstractText
Tetracenomycin (Tcm) F2 cyclase, which catalyzes the cyclization of the anthrone Tcm F2 to the naphthacenone Tcm F1 in the biosynthesis of the anthracycline antibiotic Tcm C in Streptomyces glaucescens, has been purified to homogeneity and characterized. The N-terminal sequence of the enzyme establishes that it is encoded by the tcmI gene, whose deduced product has a molecular weight of 12,728. SDS-PAGE analysis gave a single band with a molecular weight of 12,500, whereas gel-filtration chromatography yielded a molecular weight of 37,500, indicating that the Tcm F2 cyclase is a homotrimer in solution. Under pH > or = 8.0, the enzyme catalyzes the cyclization of Tcm F2 to Tcm F1 and has a Km of 121 +/- 18.2 microM and Vmax of 704 +/- 62.3 nmol.min-1.mg-1. In contrast, under pH < or = 6.5, it catalyzes the cyclization of Tcm F2 to 9-decarboxy Tcm F1, a known shunt metabolite of the Tcm C biosynthetic pathway. Tcm F2 cyclase represents the first discrete enzyme for carbon-carbon bond formation via an intramolecular aldol condensation-dehydration mechanism, a key biochemical operation proposed in the early steps of the biosynthesis of all aromatic polyketides.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11149-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Tetracenomycin F2 cyclase: intramolecular aldol condensation in the biosynthesis of tetracenomycin C in Streptomyces glaucescens.
pubmed:affiliation
School of Pharmacy, University of Wisconsin, Madison 53706.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.