[Chromosomal inversion accompanied by an enhancement of uridine phosphorylase gene expression in Escherichia coli K-12].
In thymine requiring auxotrophs of Escherichia coli the uridine phosphorylase enzyme (udp gene) can catalyze nonspecifically conversion of thymine to thymidine. By selection for effective utilization of exogenous thymine, it is possible to isolate forms with increased expression of the udp gene. Mutants with increased gene expression were isolated from the strain with transposon Tn10 within the metE gene closely linked to udp. Some mutants (designated udpPf) losing Tn10 but retaining the Met- phenotype are characterized by disturbance of recombination in the metE-udp region: they do not form Met+ transductants in P1 transduction with the wild-type donor strain. However, recovery of homology in the chromosomal metE-udp region takes place with low frequency in P1 transduction using the strain with Tn10 insertion in metE as a donor. Data obtained in transductional and conjugational experiments demonstrate that the udpPf1 mutant studied is an inversion extending about 3 min of the E. coli chromosome and including the region of chromosomal replication origin (oriC).
Kulakauskas
S T
ST
Sukhodolets
V V
VV
Mironov
A S
AS
D007446:Chromosome Inversion; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000648:ultrastructure*; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D005798:Genes, Bacterial; D009154:Mutation; D010430:Pentosyltransferases / Q000235:genetics*; D014161:Transduction, Genetic; D014543:Uridine Phosphorylase / Q000235:genetics*
D004251:DNA Transposable Elements; D010430:Pentosyltransferases; D014543:Uridine Phosphorylase
Inversiia khromosomy, soprovozhdaiushchaiasia usileniem ékspressii gena uridinfosforilazy u Escherichia coli K-12.