Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:Q9UIJ5 (
Rec
)
58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A mutant of Escherichia coli which contained no detectable
AMP nucleosidase
activity (
EC 3.2.2.4
) was produced by treatment with nitrosoguanidine and identified by a colorimetric assay for
AMP nucleosidase
in individual colonies from agar plates. Conjugation experiments indicated a close linkage between the
AMP nucleosidase
locus (amn) and his. Assays for
AMP nucleosidase
in E. coli strains with deletions in the his region established that amn is not located between attP2H and mgl . Transduction experiments with bacteriophage P1 were used to construct a linkage map in the his and amn region of the 100-min chromosome map of E. coli, which places amn at 43.3 min. A
Rec
- strain of E. coli ( FP4102 ) which carries the uvrC to his region (42.1-44.1 min) as an F' episome was used to confirm this location. The episome from FP4102 was used as the source of DNA for cloning amn. BamHI restriction fragments of the episome were inserted into the homologous site of pBR322 and used to transform the Amn- strain of E. coli to Amn+. The transforming plasmid contained a 9-kb (kilobase) insert. Partial restriction of plasmid with ClaI and religation gave a plasmid with a 6-kb insert which retains the amn gene. Restriction mapping of the plasmid has identified ClaI and PstI sites which appear to be within the amn locus. E. coli (
Rec
-) which contains the 9-kb plasmid of pBR322 containing amn overproduces
AMP nucleosidase
when grown in the presence of ampicillin. The specific activity of
AMP nucleosidase
increases from 0.016 mumol/min/mg of protein to 0.32 mumol/min/mg of protein in extracts of the wild type and the plasmid-bearing strains, respectively. A simple purification procedure yields 10 mg of homogeneous
AMP nucleosidase
from 25 g of packed cells.
...
PMID:The structural gene for AMP nucleosidase. Mapping, cloning, and overproduction of the enzyme. 632 3
