The corrected nucleotide sequences of the TaqI restriction and modification enzymes reveal a thirteen-codon overlap.
The nucleotide sequence of the genes encoding methyltransferase TaqI (M.TaqI) and restriction endonuclease TaqI (R.TaqI) with the recognition sequence, TCGA, were analyzed in clones isolated from independent libraries. The genes, originally reported as 363 and 236 codons long [Slatko et al., Nucleic Acids Res. 15 (1987) 9781-9796] were redetermined as 421 and 263 codons long, respectively. The C terminus of the taqIM gene overlaps the N terminus of the taqIR gene by 13 codons, as observed with the isoschizomeric TthHB8I restriction-modification system [Barany et al., Gene 112 (1992) 13-20]. Removal of the overlapping codons did not interfere with in vivo M.TaqI activity. We postulate the overlap plays a role in regulating taqIR expression.
Barany
F
F
Department of Microbiology, Hearst Microbiology Research Center, Cornell University Medical College, New York, NY 10021.
Slatko
B
B
Danzitz
M
M
Cowburn
D
D
Schildkraut
I
I
Wilson
G G
GG
D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D003062:Codon / Q000235:genetics; D015252:Deoxyribonucleases, Type II Site-Specific / Q000737:chemistry / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D005807:Genes, Overlapping / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000737:chemistry / Q000235:genetics*; D013824:Thermus / Q000201:enzymology* / Q000235:genetics
D003062:Codon; C059680:DNA modification methylase TaqI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases