PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 3108235-1 1987 Oligonucleotide-directed mutagenesis of the beta-lactamase gene, bla, on pBR322 was used to change the codon for the active-site serine 70, AGC, to CGC, coding for arginine. pbr322 73-79 beta-lactamase Escherichia coli 65-68 6374659-7 1984 However, expression in pBR322 was more efficient in one orientation than in the other, suggesting that one or both of the bla gene promoters contributed to skc expression. pbr322 23-29 beta-lactamase Escherichia coli 122-125 6365904-1 1984 A derivative of pBR322 has been constructed that contains both a unique EcoRI restriction site right at the beginning of the signal codons of the beta-lactamase (bla) gene and a unique BstEII site just at the end of the bla signal codons. pbr322 16-22 beta-lactamase Escherichia coli 162-165 6365904-1 1984 A derivative of pBR322 has been constructed that contains both a unique EcoRI restriction site right at the beginning of the signal codons of the beta-lactamase (bla) gene and a unique BstEII site just at the end of the bla signal codons. pbr322 16-22 beta-lactamase Escherichia coli 220-223