title: A mutation that converts serine340 of the HsdSK polypeptide to phenylalanine and its effects on restriction and modification in Escherichia coli K-12.
abstract: A hybrid hsdS gene, encoding the HsdSts + d polypeptide, was constructed by joining the proximal region of the wild-type (wt) hsdS sequence with the distal region of the hsdSts + d sequence, at the hsdS BglII site. The hybrid hsdS-Sts + d gene exerts a trans-dominant effect on restriction and modification, which points to the location of the temperature-sensitive (ts) trans-dominant (+ d) mutation in the gene hsdSts + d distal region. Sequencing of the region downstream from the HindIII target in the Escherichia coli K-12 hsdSts + d mutant was carried out. It is identical to the wt hsdS sequence (GenBank/EMBL accession number ECHSDK LV00288), except for a single base-pair transition C1245----T. The results obtained support the idea that the trans-dominant effect of the ts mutation described earlier is related to the single base-pair transition in the nonhomologous region of the hsdSts + d sequence.
authors.affiliation: Institute of Biochemistry and Physiology of Microorganisms, USSR Academy of Sciences, Pushchino on the Oka, Moscow Region.
authors.forename: V E
authors.initials: VE
authors.lastname: Zinkevich
authors.forename: M
authors.initials: M
authors.lastname: Weiserová
authors.forename: V M
authors.initials: VM
authors.lastname: Kryukov
authors.forename: J
authors.initials: J
authors.lastname: Hubácek
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D015280:DNA Restriction-Modification Enzymes / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D010649:Phenylalanine; D011994:Recombinant Proteins; D015183:Restriction Mapping; D012694:Serine; D013329:Structure-Activity Relationship
chemical_list: D015280:DNA Restriction-Modification Enzymes; D011994:Recombinant Proteins; D012694:Serine; D010649:Phenylalanine