[Site-specific mutagenesis of residue Lys-172 of phage T7 RNA polymerase: characterization of transcription properties of mutant proteins].
Lys-172 residue of bacteriophage T7 RNA polymerase (T7RP) was substituted for Leu and Gly and Lys-172, Arg-173 were deleted by the site-directed mutagenesis using synthetic oligonucleotides. The specific activity of all mutant enzymes did not differ significantly from that of the wild-type (w.t.) T7RP while for Gly-172 mutant (G172) it was somewhat lower. Leu-172 (L172) and deletion (DEL172-3) mutants were able to direct RNA synthesis on the templates lacking the T7 promoter. DEL172-3 was not able to synthesize extraneous RNA sequences in addition to the expected run-off transcripts. L172 and DEL172-3 mutants revealed altered template specificity toward various DNA templates and showed the lower stability of enzyme-promoter complexes. The possible role of Lys-172 likely belonging to an interdomain "stretch" is discussed.
Liakhov
D L
DL
Il'genfrits
Kh
Kh
Chernov
B K
BK
Dragan
S M
SM
Rechinskiĭ
V O
VO
Pokholok
D K
DK
Tunitskaia
V L
VL
Kochetkov
S N
SN
D000595:Amino Acid Sequence; D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D008239:Lysine / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010957:Plasmids; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014764:Viral Proteins
D014764:Viral Proteins; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases; D008239:Lysine
Saĭt-spetsificheskiĭ mutagenez ostatka Lys-172 RNK-polimerazy faga T7: kharakterizatsiia transkriptsionnykh svoĭstv mutantnykh belkov.