Linked Life Data

21683167

Source:http://linkedlifedata.com/resource/pubmed/id/21683167

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-8-15
pubmed:abstractText
Purine nucleoside metabolism in the archaeon Pyrococcus furiosus is catalyzed by purine nucleoside phosphorylase (PfPNP) and 5'-deoxy-5'-methylthioadenosine phosphorylase (PfMTAP). These enzymes, characterized by 50% amino acid sequence identity, show non-common features of thermophilicity and thermostability and are stabilized by intramolecular disulfide bonds. PfPNP is highly specific for 6-oxopurine nucleosides while PfMTAP is characterized by a broad substrate specificity with 6-aminopurine nucleosides as preferred substrates. Amino acid sequence comparison clearly shows that the hypothetical active sites of PfPNP and PfMTAP are almost identical and that, in analogy with human 5'-deoxy-5'-methylthioadenosine phosphorylase and human purine nucleoside phosphorylase, residue changes at level of the same crucial positions could be responsible for the switch of substrate specificity. To validate this hypothesis we changed the putative active site of PfPNP by site-directed mutagenesis. Substrate specificity and catalytic efficiency of PfPNP mutants were then analyzed by kinetic studies and compared with the wild-type enzyme. We carried out the molecular modeling of PfPNP and PfMTAP to obtain a picture of the overall enzyme structure and to identify structural features as well as interactions playing critical roles in thermostability. Finally, we utilized the structural models of mutant enzyme-substrate complex to rationalize the functional effects of the mutations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier B.V. All rights reserved.
pubmed:issnType
Print
pubmed:volume
1814
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1358-66
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Unraveling the structural and functional differences between purine nucleoside phosphorylase and 5'-deoxy-5'-methylthioadenosine phosphorylase from the archaeon Pyrococcus furiosus.
pubmed:affiliation
Dipartimento di Biochimica e Biofisica F. Cedrangolo, Seconda Università di Napoli, Via Costantinopoli 16, Napoli, Italy. giovanna.cacciapuoti@unina2.it
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't