Linked Life Data

15381407

Source:http://linkedlifedata.com/resource/pubmed/id/15381407

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2004-9-21
pubmed:databankReference
pubmed:abstractText
A cDNA encoding adenylate isopentenyltransferase (AIPT) was cloned and sequenced from cones of hop (Humulus lupulus L.) by RT-PCR using oligonucleotide primers based on the conserved sequences of Arabidopsis thaliana AIPT isozymes (AtIPT1, AtIPT3, AtIPT4, AtIPT5, AtIPT6, AtIPT7 and AtIPT8). A full-length cDNA contained a 990-bp open reading frame encoding a molecular mass of 36,603 Da protein with 329 amino acids. Further, DNA sequencing of genomic DNA revealed absence of introns in the frame. On Southern blot analysis, a single AIPT gene was detected in H. lupulus, while RT-PCR analyses demonstrated that the gene was equally expressed in almost all tissues in the plant including roots, stems, leaves and cones. The deduced amino acid sequence shares 38-51% identity to those of A. thaliana AtIPTs. A recombinant enzyme expressed in Escherichia coli catalyzed isopentenyl transfer reaction from dimethylallyldiphosphate (DMAPP) to the N6 amino group of adenosine monophosphate (AMP), adenosine diphosphate (ADP) and adenosine triphosphate (ATP), respectively. In contrast, other nucleotides; guanosine monophosphate (GMP), inosine monophosphate (IMP), cytosine monophosphate (CMP), uridine monophosphate (UMP), were not accepted as a substrate. Interestingly, steady-state kinetic analyses revealed that the isopentenylation of ADP and ATP were more efficient than that of AMP as previously reported for A. thaliana AtIPT4. Finally, H. lupulus AIPT contains the putative ATP/GTP binding motif at the N-terminal as in the case of other known isopentenyltransferases. Site-directed mutagenesis of a conserved Asp62, located right after the ATP/GTP binding motif, with Ala resulted in complete loss of enzyme activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0031-9422
pubmed:author
pubmed:copyrightInfo
Copyright 2004 Elsevier Ltd.
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2439-46
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Molecular cloning, expression, and characterization of adenylate isopentenyltransferase from hop (Humulus lupulus L.).
pubmed:affiliation
School of Pharmaceutical Sciences and the 21st Century COE Program, University of Shizuoka, 52-1 Yada, Shizuoka 422-8526, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't