抄録
A small plasmid pHY163PLK (2519bp) was constructed from the shuttle vector pHY300PLK. pHY163PLK contains the replication origin of pACYC-177, the tetracycline resistance gene (tetα1) of pAMα1 derived from Streptococcus faecalis and eight continuous unique cloning sites of a polylinker region (EcoRI, SmaI, BamHI, SalI, PstI, BglII, XbaI and HindIII). pHY163PLK, a copy-number mutant, has one base substitution in RNA I region compared with that of p15A which is the ancestor of ori-pHY163PLK. The tetα1, which codes 458 amino acids (1374bp), is highly homologous to the TcR genes of other Gram-positive bacteria but completely different from the TcR gene encoded by pBR322 in Gram-negative bacteria. The regulatory region of tetα1 (constitutive type) has an insertion of seven base pairs in the leader peptide region of a related inducible TcR gene. (key words: tetracycline resistance gene; pAMα1; Streptococcus; nucleotide sequence; amino acid sequence)
