Linked Life Data

17331946

Source:http://linkedlifedata.com/resource/pubmed/id/17331946

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2007-4-23
pubmed:abstractText
Streptomyces coelicolor RppA (Sc-RppA), a bacterial type III polyketide synthase, utilizes malonyl-CoA as both starter and extender unit substrate to form 1,3,6,8-tetrahydroxynaphthalene (THN) (therefore RppA is also known as THN synthase (THNS)). The significance of the active site Tyr(224) for substrate specificity has been established previously, and its aromatic ring is believed to be essential for RppA to select malonyl-CoA as starter unit. Herein, we describe a series of Tyr(224) mutants of Sc-RppA including Y224F, Y224L, Y224C, Y224M, and Y224A that were able to catalyze a physiological assembly of THN, albeit with lower efficiency, challenging the necessity for the Tyr(224) aromatic ring. Steady-state kinetics and radioactive substrate binding analysis of the mutant enzymes corroborated these unexpected results. Functional examination of the Tyr(224) series of RppA mutants using diverse unnatural acyl-CoA substrates revealed the unique role of malonyl-CoA as starter unit substrate for RppA, leading to the development of a novel stericelectronic constraint model.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12765-72
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Molecular analysis of the role of tyrosine 224 in the active site of Streptomyces coelicolor RppA, a bacterial type III polyketide synthase.
pubmed:affiliation
Life Sciences Institute and Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural