Cloning and functional characterization of two bacterial members of the NAT/NCS2 family in Escherichia coli
Φόρτωση...
Ημερομηνία
Συγγραφείς
Karatza, P.
Frillingos, S.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer-reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Mol Membr Biol
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The coding potential of the genome of E. coli K-12 includes YgfO and YicE, two members of the evolutionarily conserved NAT/NCS2 transporter family that are highly homologous to each other (45% residue identity) and closely related to UapA of Aspergillus nidulans, a most extensively studied microbial member of this family. YgfO and yicE were cloned from the genome, over-expressed extrachromosomally and assayed for uptake of [(3)H]xanthine and other nucleobases, in E. coli K-12, under conditions of negligible activity of the corresponding endogenous systems. Alternative, essentially equivalent functional versions of YgfO and YicE were engineered by C-terminal tagging with an epitope from the E. coli lactose permease and a biotin-acceptor domain from Klebsiella pneumoniae. Both YgfO and YicE were shown to be present in the plasma membrane of E. coli and function as specific, high-affinity transporters for xanthine (K(m) 4.2-4.6 microM for YgfO, or 2.9-3.8 microM for YicE), in a proton motive force-dependent manner; they display no detectable transport of uracil, hypoxanthine, or uric acid at external concentrations of up to 0.1 mM. Both YgfO and YicE are inefficient in recognizing uric acid or xanthine analogues modified at position 8 of the purine ring (8-methylxanthine, 8-azaxanthine, oxypurinol, allopurinol), which distinguishes them from their fungal homologues UapA and Xut1.
Περιγραφή
Λέξεις-κλειδιά
Animals, Base Sequence, Biological Transport, Cloning, Molecular, Epitopes, Escherichia coli/genetics/*metabolism, Escherichia coli Proteins/*chemistry/genetics/metabolism, Nucleobase Transport Proteins/*chemistry/genetics/metabolism, Plasmids, Sequence Alignment, Sequence Homology, Amino Acid, Structure-Activity Relationship, Substrate Specificity, Uracil/metabolism, Uric Acid/metabolism, Xanthine/metabolism
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
http://www.ncbi.nlm.nih.gov/pubmed/16096267
http://informahealthcare.com/doi/abs/10.1080/09687860500092927
http://informahealthcare.com/doi/abs/10.1080/09687860500092927
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών Υγείας. Τμήμα Ιατρικής