this plasmid contains the e. coli lac promoter , operator , a truncated beta-galactosidase ( beta-gal ) gene ( coding for the first 590 of the 1,007 amino acids of the beta-gal ) and a polylinker region ( at the 3 ' end of the beta-gal ) containing nine restriction sites .
C0005220
beta-galactosidase
C0016955
beta-gal